Beam failure recovery request for per beam group beam failure recovery

ABSTRACT

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may detect beam failure for a first beam group in a cell including the first beam group and a second beam group. The UE may selectively transmit a beam failure recovery request for the first beam group based at least in part on a determination of uplink resource availability in the second beam group. Numerous other aspects are described.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wirelesscommunication and to techniques and apparatuses for beam failurerecovery (BFR) requests for per beam group BFR.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power, or the like). Examples of such multiple-accesstechnologies include code division multiple access (CDMA) systems, timedivision multiple access (TDMA) systems, frequency-division multipleaccess (FDMA) systems, orthogonal frequency-division multiple access(OFDMA) systems, single-carrier frequency-division multiple access(SC-FDMA) systems, time division synchronous code division multipleaccess (TD-SCDMA) systems, and Long Term Evolution (LTE).LTE/LTE-Advanced is a set of enhancements to the Universal MobileTelecommunications System (UMTS) mobile standard promulgated by theThird Generation Partnership Project (3GPP).

A wireless network may include a number of base stations (BSs) that cansupport communication for a number of user equipment (UEs). A UE maycommunicate with a BS via the downlink and uplink. “Downlink” (or“forward link”) refers to the communication link from the BS to the UE,and “uplink” (or “reverse link”) refers to the communication link fromthe UE to the BS. As will be described in more detail herein, a BS maybe referred to as a Node B, a gNB, an access point (AP), a radio head, atransmit receive point (TRP), a New Radio (NR) BS, a 5G Node B, or thelike.

The above multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent user equipment to communicate on a municipal, national,regional, and even global level. NR, which may also be referred to as5G, is a set of enhancements to the LTE mobile standard promulgated bythe 3GPP. NR is designed to better support mobile broadband Internetaccess by improving spectral efficiency, lowering costs, improvingservices, making use of new spectrum, and better integrating with otheropen standards using orthogonal frequency division multiplexing (OFDM)with a cyclic prefix (CP) (CP-OFDM) on the downlink (DL), using CP-OFDMand/or SC-FDM (e.g., also known as discrete Fourier transform spreadOFDM (DFT-s-OFDM)) on the uplink (UL), as well as supportingbeamforming, multiple-input multiple-output (MIMO) antenna technology,and carrier aggregation. As the demand for mobile broadband accesscontinues to increase, further improvements in LTE, NR, and other radioaccess technologies remain useful.

SUMMARY

In some aspects, a user equipment (UE) for wireless communicationincludes memory; one or more processors coupled to the memory; andinstructions stored in the memory and operable, when executed by the oneor more processors, to cause the UE to: detect beam failure for a firstbeam group in a cell including the first beam group and a second beamgroup; and selectively transmit a beam failure recovery request for thefirst beam group based at least in part on a determination of uplinkresource availability in the second beam group.

In some aspects, a method of wireless communication performed by a UEincludes detecting beam failure for a first beam group in a cellincluding the first beam group and a second beam group; and selectivelytransmitting a beam failure recovery request for the first beam groupbased at least in part on a determination of uplink resourceavailability in the second beam group.

In some aspects, a non-transitory computer-readable medium stores one ormore instructions for wireless communication that, when executed by oneor more processors of a UE, cause the UE to: detect beam failure for afirst beam group in a cell including the first beam group and a secondbeam group; and selectively transmit a beam failure recovery request forthe first beam group based at least in part on a determination of uplinkresource availability in the second beam group.

In some aspects, an apparatus for wireless communication includes meansfor detecting beam failure for a first beam group in a cell includingthe first beam group and a second beam group; and means for selectivelytransmitting a beam failure recovery request for the first beam groupbased at least in part on a determination of uplink resourceavailability in the second beam group.

Aspects generally include a method, apparatus, system, computer programproduct, non-transitory computer-readable medium, user equipment, basestation, wireless communication device, and/or processing system assubstantially described herein with reference to and as illustrated bythe drawings and specification.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purposesof illustration and description, and not as a definition of the limitsof the claims.

While aspects are described in the present disclosure by illustration tosome examples, those skilled in the art will understand that suchaspects may be implemented in many different arrangements and scenarios.Techniques described herein may be implemented using different platformtypes, devices, systems, shapes, sizes, and/or packaging arrangements.For example, some aspects may be implemented via integrated chipembodiments or other non-module-component based devices (e.g., end-userdevices, vehicles, communication devices, computing devices, industrialequipment, retail/purchasing devices, medical devices, or artificialintelligence-enabled devices). Aspects may be implemented in chip-levelcomponents, modular components, non-modular components, non-chip-levelcomponents, device-level components, or system-level components. Devicesincorporating described aspects and features may include additionalcomponents and features for implementation and practice of claimed anddescribed aspects. For example, transmission and reception of wirelesssignals may include a number of components for analog and digitalpurposes (e.g., hardware components including antenna, RF chains, poweramplifiers, modulators, buffers, processor(s), interleavers, adders, orsummers). It is intended that aspects described herein may be practicedin a wide variety of devices, components, systems, distributedarrangements, or end-user devices of varying size, shape, andconstitution.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present disclosure can beunderstood in detail, a more particular description, briefly summarizedabove, may be had by reference to aspects, some of which are illustratedin the appended drawings. It is to be noted, however, that the appendeddrawings illustrate only certain typical aspects of this disclosure andare therefore not to be considered limiting of its scope, for thedescription may admit to other equally effective aspects. The samereference numbers in different drawings may identify the same or similarelements.

FIG. 1 is a diagram illustrating an example of a wireless network, inaccordance with the present disclosure.

FIG. 2 is a diagram illustrating an example of a base station incommunication with a UE in a wireless network, in accordance with thepresent disclosure.

FIG. 3 is a diagram illustrating an example of beam failure detection(BFD) and beam failure recovery (BFR), in accordance with the presentdisclosure.

FIG. 4 is a diagram illustrating an example of BFR for a secondary cell(Scell), in accordance with the present disclosure.

FIG. 5 is a diagram illustrating an example of a logical architecture ofa distributed radio access network (RAN), in accordance with the presentdisclosure.

FIG. 6 is a diagram illustrating an example of multi-transmit receivepoint (TRP) communication, in accordance with the present disclosure.

FIGS. 7-10 are diagrams illustrating examples associated with BFRrequests for per beam group BFR, in accordance with the presentdisclosure.

FIG. 11 is a diagram illustrating an example process associated with BFRrequests for per beam group BFR, in accordance with the presentdisclosure.

FIG. 12 is a block diagram of an example apparatus for wirelesscommunication, in accordance with the present disclosure.

DETAILED DESCRIPTION

A cell associated with a base station may serve a user equipment (UE)using different groups of beams. For example, a cell may includemultiple transmit and receive points (TRPs) that are associated withdifferent beam groups. A UE may be configured to perform per beam group(e.g., per TRP) beam failure detection (BFD). In this case, the UE maydetect a beam failure for beam group in a cell without detecting beamfailure for another beam group in the cell. Because detecting beamfailure for one beam group may not mean that all beams in the cell fail,the UE may be able to transmit a per beam group (e.g., per TRP) beamfailure recovery (BFR) request via a beam in another beam group in thecell. However, in some cases, the UE may not be able to select an uplinkresource for transmitting a per beam group BFR request. For example,there may be no configured dedicated uplink resources for transmitting aper beam group BFR request, or a configured dedicated uplink resourcefor transmitting a per beam group BFR request may be associated with thebeam group for which beam failure is detected. In such cases, the UE maynot be able to quickly request per beam group BFR. For example, the UEmay need to wait until beam failure is detected for the whole cell torequest BFR at a cell level, resulting in increased delay in beamfailure recovery, increased latency of uplink and/or downlink traffic,and decreased network speed.

Some techniques and apparatuses described herein enable a UE to detectbeam failure for a first beam group in a cell including a first beamgroup and a second beam group. The UE may selectively transmit a BFRrequest for the first beam group based at least in part on adetermination of uplink resource availability in the second beam group.In some aspects, the first beam group may be associated with a first TRPand the second beam group may be associated with a second TRP. In someaspects, based at least in part on the determination of the uplinkresource availability in the second beam group, the UE may transmit aBFR scheduling request on a beam of the second beam group using a PUCCHscheduling request resource dedicated to BFR for the first beam group,the UE may transmit a BFR scheduling request using an earliest availablePUCCH scheduling request resource on a beam of the second beam group, orthe UE may transmit a BFR MAC-CE using an existing scheduled PUSCHresource on a beam of the second beam group. As a result, the UE mayselect an available uplink resource in a case in which there are nodedicated resources configured in the second beam group. This may reducecases in which the UE cannot transmit per beam group or per TRP BFRrequests, thus reducing delays in beam failure recover, decreasinglatency of uplink and/or downlink traffic, and increasing network speed.Furthermore, the UE may select the uplink resource based at least inpart on a determination of an earliest available network resource, whichmay decrease latency associated with requesting BFR.

Various aspects of the disclosure are described more fully hereinafterwith reference to the accompanying drawings. This disclosure may,however, be embodied in many different forms and should not be construedas limited to any specific structure or function presented throughoutthis disclosure. Rather, these aspects are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art. Based on theteachings herein, one skilled in the art should appreciate that thescope of the disclosure is intended to cover any aspect of thedisclosure disclosed herein, whether implemented independently of orcombined with any other aspect of the disclosure. For example, anapparatus may be implemented or a method may be practiced using anynumber of the aspects set forth herein. In addition, the scope of thedisclosure is intended to cover such an apparatus or method which ispracticed using other structure, functionality, or structure andfunctionality in addition to or other than the various aspects of thedisclosure set forth herein. It should be understood that any aspect ofthe disclosure disclosed herein may be embodied by one or more elementsof a claim.

Several aspects of telecommunication systems will now be presented withreference to various apparatuses and techniques. These apparatuses andtechniques will be described in the following detailed description andillustrated in the accompanying drawings by various blocks, modules,components, circuits, steps, processes, algorithms, or the like(collectively referred to as “elements”). These elements may beimplemented using hardware, software, or combinations thereof. Whethersuch elements are implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem.

It should be noted that while aspects may be described herein usingterminology commonly associated with a 5G or NR radio access technology(RAT), aspects of the present disclosure can be applied to other RATs,such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G (e.g., 6G).

FIG. 1 is a diagram illustrating an example of a wireless network 100,in accordance with the present disclosure. The wireless network 100 maybe or may include elements of a 5G (NR) network and/or an LTE network,among other examples. The wireless network 100 may include a number ofbase stations 110 (shown as BS 110 a, BS 110 b, BS 110 c, and BS 110 d)and other network entities. A base station (BS) is an entity thatcommunicates with UEs and may also be referred to as an NR BS, a Node B,a gNB, a 5G node B (NB), an access point, a transmit receive point(TRP), or the like. Each BS may provide communication coverage for aparticular geographic area. In 3GPP, the term “cell” can refer to acoverage area of a BS and/or a BS subsystem serving this coverage area,depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or another type of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a closed subscriber group (CSG)). A BS for a macro cell may bereferred to as a macro BS. A BS for a pico cell may be referred to as apico BS. A BS for a femto cell may be referred to as a femto BS or ahome BS. In the example shown in FIG. 1, a BS 110 a may be a macro BSfor a macro cell 102 a, a BS 110 b may be a pico BS for a pico cell 102b, and a BS 110 c may be a femto BS for a femto cell 102 c. A BS maysupport one or multiple (e.g., three) cells. The terms “eNB”, “basestation”, “NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” maybe used interchangeably herein.

In some aspects, a cell may not necessarily be stationary, and thegeographic area of the cell may move according to the location of amobile BS. In some aspects, the BSs may be interconnected to one anotherand/or to one or more other BSs or network nodes (not shown) in thewireless network 100 through various types of backhaul interfaces, suchas a direct physical connection or a virtual network, using any suitabletransport network.

Wireless network 100 may also include relay stations. A relay station isan entity that can receive a transmission of data from an upstreamstation (e.g., a BS or a UE) and send a transmission of the data to adownstream station (e.g., a UE or a BS). A relay station may also be aUE that can relay transmissions for other UEs. In the example shown inFIG. 1, a relay BS 110 d may communicate with macro BS 110 a and a UE120 d in order to facilitate communication between BS 110 a and UE 120d. A relay BS may also be referred to as a relay station, a relay basestation, a relay, or the like.

Wireless network 100 may be a heterogeneous network that includes BSs ofdifferent types, such as macro BSs, pico BSs, femto BSs, relay BSs, orthe like. These different types of BSs may have different transmit powerlevels, different coverage areas, and different impacts on interferencein wireless network 100. For example, macro BSs may have a high transmitpower level (e.g., 5 to 40 watts) whereas pico BSs, femto BSs, and relayBSs may have lower transmit power levels (e.g., 0.1 to 2 watts).

A network controller 130 may couple to a set of BSs and may providecoordination and control for these BSs. Network controller 130 maycommunicate with the BSs via a backhaul. The BSs may also communicatewith one another, e.g., directly or indirectly via a wireless orwireline backhaul.

UEs 120 (e.g., 120 a, 120 b, 120 c) may be dispersed throughout wirelessnetwork 100, and each UE may be stationary or mobile. A UE may also bereferred to as an access terminal, a terminal, a mobile station, asubscriber unit, a station, or the like. A UE may be a cellular phone(e.g., a smart phone), a personal digital assistant (PDA), a wirelessmodem, a wireless communication device, a handheld device, a laptopcomputer, a cordless phone, a wireless local loop (WLL) station, atablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook,a medical device or equipment, biometric sensors/devices, wearabledevices (smart watches, smart clothing, smart glasses, smart wristbands, smart jewelry (e.g., smart ring, smart bracelet)), anentertainment device (e.g., a music or video device, or a satelliteradio), a vehicular component or sensor, smart meters/sensors,industrial manufacturing equipment, a global positioning system device,or any other suitable device that is configured to communicate via awireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolvedor enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEsinclude, for example, robots, drones, remote devices, sensors, meters,monitors, and/or location tags, that may communicate with a basestation, another device (e.g., remote device), or some other entity. Awireless node may provide, for example, connectivity for or to a network(e.g., a wide area network such as Internet or a cellular network) via awired or wireless communication link. Some UEs may be consideredInternet-of-Things (IoT) devices, and/or may be implemented as NB-IoT(narrowband internet of things) devices. Some UEs may be considered aCustomer Premises Equipment (CPE). UE 120 may be included inside ahousing that houses components of UE 120, such as processor componentsand/or memory components. In some aspects, the processor components andthe memory components may be coupled together. For example, theprocessor components (e.g., one or more processors) and the memorycomponents (e.g., a memory) may be operatively coupled, communicativelycoupled, electronically coupled, and/or electrically coupled.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular RAT andmay operate on one or more frequencies. A RAT may also be referred to asa radio technology, an air interface, or the like. A frequency may alsobe referred to as a carrier, a frequency channel, or the like. Eachfrequency may support a single RAT in a given geographic area in orderto avoid interference between wireless networks of different RATs. Insome cases, NR or 5G RAT networks may be deployed.

In some aspects, two or more UEs 120 (e.g., shown as UE 120 a and UE 120e) may communicate directly using one or more sidelink channels (e.g.,without using a base station 110 as an intermediary to communicate withone another). For example, the UEs 120 may communicate usingpeer-to-peer (P2P) communications, device-to-device (D2D)communications, a vehicle-to-everything (V2X) protocol (e.g., which mayinclude a vehicle-to-vehicle (V2V) protocol or avehicle-to-infrastructure (V2I) protocol), and/or a mesh network. Inthis case, the UE 120 may perform scheduling operations, resourceselection operations, and/or other operations described elsewhere hereinas being performed by the base station 110.

Devices of wireless network 100 may communicate using theelectromagnetic spectrum, which may be subdivided based on frequency orwavelength into various classes, bands, channels, or the like. Forexample, devices of wireless network 100 may communicate using anoperating band having a first frequency range (FR1), which may span from410 MHz to 7.125 GHz, and/or may communicate using an operating bandhaving a second frequency range (FR2), which may span from 24.25 GHz to52.6 GHz. The frequencies between FR1 and FR2 are sometimes referred toas mid-band frequencies. Although a portion of FR1 is greater than 6GHz, FR1 is often referred to as a “sub-6 GHz” band. Similarly, FR2 isoften referred to as a “millimeter wave” band despite being differentfrom the extremely high frequency (EHF) band (30 GHz-300 GHz) which isidentified by the International Telecommunications Union (ITU) as a“millimeter wave” band. Thus, unless specifically stated otherwise, itshould be understood that the term “sub-6 GHz” or the like, if usedherein, may broadly represent frequencies less than 6 GHz, frequencieswithin FR1, and/or mid-band frequencies (e.g., greater than 7.125 GHz).Similarly, unless specifically stated otherwise, it should be understoodthat the term “millimeter wave” or the like, if used herein, may broadlyrepresent frequencies within the EHF band, frequencies within FR2,and/or mid-band frequencies (e.g., less than 24.25 GHz). It iscontemplated that the frequencies included in FR1 and FR2 may bemodified, and techniques described herein are applicable to thosemodified frequency ranges.

As indicated above, FIG. 1 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 1.

FIG. 2 is a diagram illustrating an example 200 of a base station 110 incommunication with a UE 120 in a wireless network 100, in accordancewith the present disclosure. Base station 110 may be equipped with Tantennas 234 a through 234 t, and UE 120 may be equipped with R antennas252 a through 252 r, where in general T≥1 and R≥1.

At base station 110, a transmit processor 220 may receive data from adata source 212 for one or more UEs, select one or more modulation andcoding schemes (MCS) for each UE based at least in part on channelquality indicators (CQIs) received from the UE, process (e.g., encodeand modulate) the data for each UE based at least in part on the MCS(s)selected for the UE, and provide data symbols for all UEs. Transmitprocessor 220 may also process system information (e.g., for semi-staticresource partitioning information (SRPI)) and control information (e.g.,CQI requests, grants, and/or upper layer signaling) and provide overheadsymbols and control symbols. Transmit processor 220 may also generatereference symbols for reference signals (e.g., a cell-specific referencesignal (CRS) or a demodulation reference signal (DMRS)) andsynchronization signals (e.g., a primary synchronization signal (PSS) ora secondary synchronization signal (SSS)). A transmit (TX)multiple-input multiple-output (MIMO) processor 230 may perform spatialprocessing (e.g., precoding) on the data symbols, the control symbols,the overhead symbols, and/or the reference symbols, if applicable, andmay provide T output symbol streams to T modulators (MODs) 232 a through232 t. Each modulator 232 may process a respective output symbol stream(e.g., for OFDM) to obtain an output sample stream. Each modulator 232may further process (e.g., convert to analog, amplify, filter, andupconvert) the output sample stream to obtain a downlink signal. Tdownlink signals from modulators 232 a through 232 t may be transmittedvia T antennas 234 a through 234 t, respectively.

At UE 120, antennas 252 a through 252 r may receive the downlink signalsfrom base station 110 and/or other base stations and may providereceived signals to demodulators (DEMODs) 254 a through 254 r,respectively. Each demodulator 254 may condition (e.g., filter, amplify,downconvert, and digitize) a received signal to obtain input samples.Each demodulator 254 may further process the input samples (e.g., forOFDM) to obtain received symbols. A MIMO detector 256 may obtainreceived symbols from all R demodulators 254 a through 254 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. A receive processor 258 may process (e.g., demodulateand decode) the detected symbols, provide decoded data for UE 120 to adata sink 260, and provide decoded control information and systeminformation to a controller/processor 280. The term“controller/processor” may refer to one or more controllers, one or moreprocessors, or a combination thereof. A channel processor may determinea reference signal received power (RSRP) parameter, a received signalstrength indicator (RSSI) parameter, a reference signal received quality(RSRQ) parameter, and/or a channel quality indicator (CQI) parameter,among other examples. In some aspects, one or more components of UE 120may be included in a housing 284.

Network controller 130 may include communication unit 294,controller/processor 290, and memory 292. Network controller 130 mayinclude, for example, one or more devices in a core network. Networkcontroller 130 may communicate with base station 110 via communicationunit 294.

Antennas (e.g., antennas 234 a through 234 t and/or antennas 252 athrough 252 r) may include, or may be included within, one or moreantenna panels, antenna groups, sets of antenna elements, and/or antennaarrays, among other examples. An antenna panel, an antenna group, a setof antenna elements, and/or an antenna array may include one or moreantenna elements. An antenna panel, an antenna group, a set of antennaelements, and/or an antenna array may include a set of coplanar antennaelements and/or a set of non-coplanar antenna elements. An antennapanel, an antenna group, a set of antenna elements, and/or an antennaarray may include antenna elements within a single housing and/orantenna elements within multiple housings. An antenna panel, an antennagroup, a set of antenna elements, and/or an antenna array may includeone or more antenna elements coupled to one or more transmission and/orreception components, such as one or more components of FIG. 2.

On the uplink, at UE 120, a transmit processor 264 may receive andprocess data from a data source 262 and control information (e.g., forreports that include RSRP, RSSI, RSRQ, and/or CQI) fromcontroller/processor 280. Transmit processor 264 may also generatereference symbols for one or more reference signals. The symbols fromtransmit processor 264 may be precoded by a TX MIMO processor 266 ifapplicable, further processed by modulators 254 a through 254 r (e.g.,for DFT-s-OFDM or CP-OFDM), and transmitted to base station 110. In someaspects, a modulator and a demodulator (e.g., MOD/DEMOD 254) of the UE120 may be included in a modem of the UE 120. In some aspects, the UE120 includes a transceiver. The transceiver may include any combinationof antenna(s) 252, modulators and/or demodulators 254, MIMO detector256, receive processor 258, transmit processor 264, and/or TX MIMOprocessor 266. The transceiver may be used by a processor (e.g.,controller/processor 280) and memory 282 to perform aspects of any ofthe methods described herein (for example, as described with referenceto FIGS. 7-11).

At base station 110, the uplink signals from UE 120 and other UEs may bereceived by antennas 234, processed by demodulators 232, detected by aMIMO detector 236 if applicable, and further processed by a receiveprocessor 238 to obtain decoded data and control information sent by UE120. Receive processor 238 may provide the decoded data to a data sink239 and the decoded control information to controller/processor 240.Base station 110 may include communication unit 244 and communicate tonetwork controller 130 via communication unit 244. Base station 110 mayinclude a scheduler 246 to schedule UEs 120 for downlink and/or uplinkcommunications. In some aspects, a modulator and a demodulator (e.g.,MOD/DEMOD 232) of the base station 110 may be included in a modem of thebase station 110. In some aspects, the base station 110 includes atransceiver. The transceiver may include any combination of antenna(s)234, modulators and/or demodulators 232, MIMO detector 236, receiveprocessor 238, transmit processor 220, and/or TX MIMO processor 230. Thetransceiver may be used by a processor (e.g., controller/processor 240)and memory 242 to perform aspects of any of the methods describedherein, for example, as described with reference to FIGS. 7-11.

Controller/processor 240 of base station 110, controller/processor 280of UE 120, and/or any other component(s) of FIG. 2 may perform one ormore techniques associated with beam failure recovery (BFR) requests forper beam group BFR, as described in more detail elsewhere herein. Insome aspects, the TRP described herein is the base station 110, isincluded in the base station 110, or includes one or more components ofthe base station 110 shown in FIG. 2. For example, controller/processor240 of base station 110, controller/processor 280 of UE 120, and/or anyother component(s) of FIG. 2 may perform or direct operations of, forexample, process 1100 of FIG. 11, and/or other processes as describedherein. Memories 242 and 282 may store data and program codes for basestation 110 and UE 120, respectively. In some aspects, memory 242 and/ormemory 282 may include a non-transitory computer-readable medium storingone or more instructions (e.g., code and/or program code) for wirelesscommunication. For example, the one or more instructions, when executed(e.g., directly, or after compiling, converting, and/or interpreting) byone or more processors of the base station 110 and/or the UE 120, maycause the one or more processors, the UE 120, and/or the base station110 to perform or direct operations of, for example, process 1100 ofFIG. 11, and/or other processes as described herein. In some aspects,executing instructions may include running the instructions, convertingthe instructions, compiling the instructions, and/or interpreting theinstructions, among other examples.

In some aspects, the UE 120 includes means for detecting beam failurefor a first beam group in a cell including the first beam group and asecond beam group; and/or means for selectively transmitting a beamfailure recovery request for the first beam group based at least in parton a determination of uplink resource availability in the second beamgroup. The means for the UE 120 to perform operations described hereinmay include, for example, one or more of antenna 252, demodulator 254,MIMO detector 256, receive processor 258, transmit processor 264, TXMIMO processor 266, modulator 254, controller/processor 280, or memory282.

While blocks in FIG. 2 are illustrated as distinct components, thefunctions described above with respect to the blocks may be implementedin a single hardware, software, or combination component or in variouscombinations of components. For example, the functions described withrespect to the transmit processor 264, the receive processor 258, and/orthe TX MIMO processor 266 may be performed by or under the control ofcontroller/processor 280.

As indicated above, FIG. 2 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 2.

FIG. 3 is a diagram illustrating an example 300 of beam failuredetection (BFD) and BFR, in accordance with the present disclosure.Example 300 shows BFR for a primary carrier component, or primary cell(Pcell), configured for a UE. Carrier aggregation is a technology thatenables two or more component carriers (sometimes referred to ascarriers) to be combined (e.g., into a single channel) for a UE toenhance data capacity. In carrier aggregation, a UE may be configuredwith a primary carrier or Pcell and one or more secondary carriers orsecondary cells (Scells). In some aspects, the Pcell may carry controlinformation for scheduling data communications on the one or moreScells. The BFR shown in FIG. 3 may be used for the Pcell in a case inwhich carrier aggregation is configured for the UE. The BFR shown inFIG. 3 may also be used for a PScell (e.g., a Pcell of a secondary cellgroup) in a case in which dual connectivity and carrier aggregation areconfigured for the UE.

As shown in FIG. 3, and by reference number 305, a UE may receive (e.g.,on the Pcell or PScell) BFD reference signals transmitted by a basestation. The UE may perform BFD based at least in part on measurementsperformed on the BFD reference signals. The BFD reference signals mayinclude channel state information reference signals (CSI-RSs)transmitted using periodic CSI-RS resources configured via a parameterin a radio resource control (RRC) message. In some examples, a BFDreference signal set may be configured with up to two reference signalsassociated with a single antenna port. In a case in which the BFDreference signal set is not configured by the base station, referencesignal sets indicated by active transmission configuration indicator(TCI) states of control resource sets (CORESETs) monitored by the UE maybe used for BFD. In some examples, in a case in which, for an activeCORESET, there are two reference signal indices, the reference signalhaving a quasi co-location (QCL) parameter of type D may be used forBFD.

As shown by reference number 310, the UE may detect a beam failure basedat least in part on the BFD reference signals. The physical layer in theUE may assess radio link quality by measuring RSRP of the BFD referencesignals and comparing the RSRP measurements with a threshold (Qout). Ifthe RSRP measurements are less than Qout, the physical layer may providea beam failure indication (e.g., out of service indication) to a higherlayer of the UE (e.g., the medium access control (MAC) layer), which mayincrement a beam failure indicator counter. The UE may detect beamfailure based at least in part on a threshold number of beam failureindications within a certain time duration (e.g., a BFD timer).

As shown by reference number 315, based at least in part on detecting abeam failure, the UE may perform candidate beam detection to select acandidate beam for BFR. The UE may perform candidate beam detectionbased at least in part on periodic CSI-RSs and/or synchronization signalblocks (SSBs) configured for a number of beam candidates. In someexamples, CSI-RS/SSB resources may be configured for up to 16 beamcandidates with corresponding random access preamble indices. Upon arequest from a higher layer (e.g., the MAC layer), the physical layer ofthe UE may detect a reference signal with an RSRP that satisfies athreshold (Qin) and provide the reference signal index to the higherlayers.

As shown by reference number 320, the UE may then transmit a randomaccess channel (RACH) BFR request to the base station. For example, theUE may initiate a contention free RACH procedure based on the randomaccess resource (e.g., the random access preamble index) associated withthe selected reference signal index corresponding to the selectedcandidate beam.

As shown by reference number 325, the UE may receive a BFR responsebased at least in part on transmitting the RACH BFR request. The UE maymonitor a physical downlink control channel (PDCCH) search space set todetect a PDCCH communication with downlink control information (DCI)format with a cyclic redundancy check (CRC) scrambled by a cell radionetwork temporary identifier (C-RNTI) or an MCS cell radio networktemporary identifier (MCS-C-RNTI), starting a certain number of slotsafter transmitting the RACH request (e.g., starting from slot n+4). Inthis case, the UE monitors for a random access response (e.g., the PDCCHcommunication), which is the BFR response. The search space for thePDCCH monitoring may be identified by a recovery search space ID, and,in some examples, the CORESET associated with a secondarysynchronization signal (SSS) provided by the recovery search space IDmay not be used for any other SSS. For PDCCH monitoring in the SSSprovided by the recovery search space ID and for corresponding physicaldownlink shared channel (PDSCH) reception, the UE may us the same QCLparameters as those associated with the reference signal index selectedduring candidate beam selection (e.g., the QCL parameters associatedwith the selected candidate beam) until the UE receives an activationfor a TCI state associated with another beam.

In a case in which the UE receives the PDCCH communication with CRCscrambled by C-RNTI or MCS-C-RNTI within a time window associated withthe contention free RACH procedure, the BFR may be complete for the UE.In this case, after a certain number of symbols (e.g., 28 symbols) froma last symbols of the first PDCCH reception, in the search space beingmonitored by the UE, for which the UE detects a DCI format scrambled byC-RNTI or MCS-C-RNTI, the UE may use the same QCL parameters as thoseassociated with the selected reference signal index for PDCCH monitoringin a CORESET with index 0.

In a case in which the UE does not receive the PDCCH communication withCRC scrambled by C-RNTI or MCS-C-RNTI with the time window associatedwith the contention free RACH procedure, the UE may initiate acontention-based RACH procedure to transmit the BFR request to the basestation. The UE may then monitor the search space for a PDCCHcommunication with CRC scrambled by C-RNTI or MCS-C-RNTI in response tothe contention-based RACH request. In a case, in which the UE does notreceive the BFR response in a time window associated with thecontention-based RACH procedure, or in a case in which a BFR timer,which starts upon detection of beam failure, expires prior to receivinga BFR response, the UE may declare a radio link failure.

As indicated above, FIG. 3 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 3.

FIG. 4 is a diagram illustrating an example 400 of BFR for an Scell, inaccordance with the present disclosure. As described above, an Scell isa secondary component carrier configured for a UE in carrieraggregation.

As shown in FIG. 4, and by reference number 405, the UE may receive BFDreference signals on the Scell. The UE may perform BFD based at least inpart on measurements (e.g., RSRP measurements) performed on the BFDreference signals. As shown by reference number 410, the UE may detectbeam failure on the Scell based at least in part on the measurementsperformed on the BFD reference signals.

As shown by reference number 415, the UE may transmit, to a base stationon the Pcell or PScell, a link recovery request (LRR). In some examples,the UE may transmit the LRR on an Scell configured with a physicaluplink control channel (PUCCH) (PUCCH-Scell), in which PUCCH BFR isconfigured. This LRR may be a scheduling request for requesting anuplink grant to schedule an uplink transmission of a BFR MAC controlelement (MAC-CE). For example, the LRR may be a PUCCH communication thatuses PUCCH format 0 or PUCCH format 1.

As shown by reference number 420, the base station may transmit, to theUE on the Pcell, PScell, or PUCCH-Scell, an uplink grant based at leastin part on the LRR. For example, the uplink grant may be included in DCIwith CRC scrambled with C-RNTI or MCS-C-RNTI. The uplink grant mayschedule a physical uplink shared channel (PUSCH) resource in which theUE may transmit the BFR MAC-CE.

As shown by reference number 425, the UE may perform candidate beamdetection to select a candidate beam for BFR. The UE may be configuredto receive a reference signal (or reference signal set) on each beam ofa list of candidate beams. In some examples, the UE may be configuredwith up to 64 reference signal resources (corresponding to 64 beams).The UE may receive the reference signals on different beams on thefailed Scell or another component carrier in a same frequency band asthe failed Scell. In this case, the UE is not performing a RACHprocedure, so the reference signal resources configured for thecandidate beams may not be associated with RACH resources. The UE mayselect a candidate beam for which the RSRP of corresponding referencesignals satisfies a threshold (Qin).

As shown by reference number 430, the UE may transmit, to the basestation, the BFR MAC-CE. For example, the UE may transmit the BFR MAC-CEusing the PUSCH resource scheduled by the uplink grant. Alternatively,in some examples, if the UE has an already scheduled uplink grant, theUE may transmit the BFR MAC-CE in the already scheduled uplink grantwithout transmitting the LRR or receiving the uplink grant. The BFRMAC-CE may include an indication of the failed Scell (e.g., an index ofthe Scell) and an indication of the selected candidate beam for theScell. Because the BFR MAC-CE may be transmitted in a scheduled PUSCHresource, the BFR MAC-CE may be transmitted on any component carrier,including the Scell.

As shown by reference number 435, the UE may receive, from the basestation, a BFR response. In this case, the BFR response may be aresponse to the BFR MAC-CE. The response to the BFR MAC-CE may be anuplink grant to schedule a new transmission (e.g., with a toggled newdata indicator (NDI)) for a same hybrid automatic repeat request (HARQ)process as the PUSCH transmission carrying the BFR MAC-CE. In a case inwhich a new beam (e.g., the selected beam candidate) is reported in theBFR MAC-CE after a certain number of symbols (e.g., 28 symbols) from theend of the BFR response (e.g., the end of the PDCCH communication), allCORESET beams on the failed Scell may be reset to the new beam. In acase in which the failed Scell is a PUCCH-Scell, spatial relationshipinformation for the PUCCH may be configured for the new beam after thecertain number of symbols (e.g., 28 symbols) from the end of the BFRresponse. In a case in which the LRR is not transmitted on the failedScell, PUCCH beams on the failed Scell may be reset to the new beamafter the certain number of symbols (e.g., 28 symbols) from the end ofthe BFR response.

As indicated above, FIG. 4 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 4.

FIG. 5 is a diagram illustrating an example 500 of a logicalarchitecture of a distributed radio access network (RAN), in accordancewith the present disclosure.

A 5G access node 505 may include an access node controller 510. Theaccess node controller 510 may be a central unit (CU) of the distributedRAN. In some aspects, a backhaul interface to a 5G core network 515 mayterminate at the access node controller 510. The 5G core network 515 mayinclude a 5G control plane component 520 and a 5G user plane component525 (e.g., a 5G gateway), and the backhaul interface for one or both ofthe 5G control plane and the 5G user plane may terminate at the accessnode controller 510. Additionally, or alternatively, a backhaulinterface to one or more neighbor access nodes 530 (e.g., another 5Gaccess node 505 and/or an LTE access node) may terminate at the accessnode controller 510.

The access node controller 510 may include and/or may communicate withone or more TRPs 535 (e.g., via an F1 Control (F1-C) interface and/or anF1 User (F1-U) interface). A TRP 535 may be a distributed unit (DU) ofthe distributed RAN. In some aspects, a TRP 535 may correspond to a basestation 110 described above in connection with FIG. 1. For example,different TRPs 535 may be included in different base stations 110.Additionally, or alternatively, multiple TRPs 535 may be included in asingle base station 110. In some aspects, a base station 110 may includea CU (e.g., access node controller 510) and/or one or more DUs (e.g.,one or more TRPs 535). In some cases, a TRP 535 may be referred to as acell, a panel, an antenna array, or an array. In some aspects, a cellassociated with a base station 110 may have multiple TRPs 535.

In some aspects, multiple TRPs 535 may transmit communications (e.g.,the same communication or different communications) in the sametransmission time interval (TTI) (e.g., a slot, a mini-slot, a subframe,or a symbol) or different TTIs using different QCL relationships (e.g.,different spatial parameters, different transmission configurationindicator (TCI) states, different precoding parameters, and/or differentbeamforming parameters). In some aspects, a TCI state may be used toindicate one or more QCL relationships. In some aspects, different beamgroups (e.g., corresponding to different TCI states and/or QCLrelationships) may be configured for different TRPs 535 in a cell. A TRP535 may be configured to individually (e.g., using dynamic selection) orjointly (e.g., using joint transmission with one or more other TRPs 535)serve traffic to a UE 120.

As indicated above, FIG. 5 is provided as an example. Other examples maydiffer from what was described with regard to FIG. 5.

FIG. 6 is a diagram illustrating an example 600 of multi-TRPcommunication (sometimes referred to as multi-panel communication), inaccordance with the present disclosure. As shown in FIG. 6, multipleTRPs 605 may communicate with the same UE 120. A TRP 605 may correspondto a TRP 535 described above in connection with FIG. 5.

The multiple TRPs 605 (shown as TRP A and TRP B) may communicate withthe same UE 120 in a coordinated manner (e.g., using coordinatedmultipoint transmissions) to improve reliability and/or increasethroughput. The TRPs 605 may coordinate such communications via aninterface between the TRPs 605 (e.g., a backhaul interface and/or anaccess node controller 510). The interface may have a smaller delayand/or higher capacity when the TRPs 605 are co-located at the same basestation 110 (e.g., when the TRPs 605 are different antenna arrays orpanels of the same base station 110), and may have a larger delay and/orlower capacity (as compared to co-location) when the TRPs 605 arelocated at different base stations 110. The different TRPs 605 maycommunicate with the UE 120 using different QCL relationships (e.g.,different TCI states), different demodulation reference signal (DMRS)ports, and/or different layers (e.g., of a multi-layer communication).

In a first multi-TRP transmission mode (e.g., Mode 1), a single physicaldownlink control channel (PDCCH) may be used to schedule downlink datacommunications for a single physical downlink shared channel (PDSCH). Inthis case, multiple TRPs 605 (e.g., TRP A and TRP B) may transmitcommunications to the UE 120 on the same PDSCH. For example, acommunication may be transmitted using a single codeword with differentspatial layers for different TRPs 605 (e.g., where one codeword maps toa first set of layers transmitted by a first TRP 605 and maps to asecond set of layers transmitted by a second TRP 605). As anotherexample, a communication may be transmitted using multiple codewords,where different codewords are transmitted by different TRPs 605 (e.g.,using different sets of layers). In either case, different TRPs 605 mayuse different QCL relationships (e.g., different TCI states) fordifferent DMRS ports corresponding to different layers. For example, afirst TRP 605 may use a first QCL relationship or a first TCI state fora first set of DMRS ports corresponding to a first set of layers, and asecond TRP 605 may use a second (different) QCL relationship or a second(different) TCI state for a second (different) set of DMRS portscorresponding to a second (different) set of layers. In some aspects, aTCI state in downlink control information (DCI) (e.g., transmitted onthe PDCCH, such as DCI format 1_0 or DCI format 1_1) may indicate thefirst QCL relationship (e.g., by indicating a first TCI state) and thesecond QCL relationship (e.g., by indicating a second TCI state). Thefirst and the second TCI states may be indicated using a TCI field inthe DCI. In general, the TCI field can indicate a single TCI state (forsingle-TRP transmission) or multiple TCI states (for multi-TRPtransmission as discussed here) in this multi-TRP transmission mode(e.g., Mode 1).

In a second multi-TRP transmission mode (e.g., Mode 2), multiple PDCCHsmay be used to schedule downlink data communications for multiplecorresponding PDSCHs (e.g., one PDCCH for each PDSCH). In this case, afirst PDCCH may schedule a first codeword to be transmitted by a firstTRP 605, and a second PDCCH may schedule a second codeword to betransmitted by a second TRP 605. Furthermore, first DCI (e.g.,transmitted by the first TRP 605) may schedule a first PDSCHcommunication associated with a first set of DMRS ports with a first QCLrelationship (e.g., indicated by a first TCI state) for the first TRP605, and second DCI (e.g., transmitted by the second TRP 605) mayschedule a second PDSCH communication associated with a second set ofDMRS ports with a second QCL relationship (e.g., indicated by a secondTCI state) for the second TRP 605. In this case, DCI (e.g., having DCIformat 1_0 or DCI format 1_1) may indicate a corresponding TCI state fora TRP 605 corresponding to the DCI. The TCI field of a DCI indicates thecorresponding TCI state (e.g., the TCI field of the first DCI indicatesthe first TCI state and the TCI field of the second DCI indicates thesecond TCI state).

The TRPs 605 may communicate with the UE 120 using different sets ofbeams. For example, the first TRP 605 (e.g., TRP A) may communicate withthe UE 120 using one or more beams in a first beam group (e.g.,corresponding to a first set of TCI states and/or QCL relationships),and second TRP 605 (e.g., TRP B) may communicate with the UE 120 usingone or more beams in a second beam group (e.g., corresponding to asecond set of TCI states and/or QCL relationships). In some aspects, theUE 120 may be configured with separate BFD reference signal sets for themultiple TRPs 605. In this case, the UE 120 may perform per TRP (or perbeam group) BFD.

As indicated above, FIG. 6 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 6.

A cell may serve a UE using different groups of beams. For example, asdescribed above in connection with FIG. 6, each group of beams in a cellmay correspond to a respective TRP of multiple TRPs in the cell. A UEmay be configured with different BFD reference signal sets for differentbeam groups and/or TRPs in a cell. The UE may monitor the different BFDreference signals to perform per beam group and/or per TRP BFD. In thiscase, the UE may detect a beam failure for one TRP in a cell withoutdetecting beam failure for another TRP in the cell. Because detectingbeam failure for one TRP may not mean that all beams in the cell fail,the UE may be able to transmit a per TRP BFR request via another TRP.However, in some cases, the UE may not be able to select an uplinkresource for transmitting a per TRP (or per beam group) BFR request. Forexample, there may be no configured dedicated uplink resources fortransmitting a per TRP BFR request, or a configured dedicated uplinkresource for transmitting a per TRP BFR request may be associated withthe TRP for which beam failure is detected. In such cases, the UE maynot be able to quickly request per TRP BFR. For example, the UE may needto wait until beam failure is detected for the whole cell to requestbeam failure, resulting in increased delay in beam failure recovery,increased latency of uplink and/or downlink traffic, and decreasednetwork speed.

Some techniques and apparatuses described herein enable a UE to detectbeam failure for a first beam group in a cell including a first beamgroup and a second beam group. The UE may selectively transmit a BFRrequest for the first beam group based at least in part on adetermination of uplink resource availability in the second beam group.In some aspects, the first beam group may be associated with a first TRPand the second beam group may be associated with a second TRP. In someaspects, based at least in part on the determination of the uplinkresource availability in the second beam group, the UE may transmit aBFR scheduling request on a beam of the second beam group using a PUCCHscheduling request resource dedicated to BFR for the first beam group,the UE may transmit a BFR scheduling request using an earliest availablePUCCH scheduling request resource on a beam of the second beam group, orthe UE may transmit a BFR MAC-CE using an existing scheduled PUSCHresource on a beam of the second beam group. As a result, the UE mayselect an available uplink resource in a case in which there are nodedicated resources configured in the second beam group. This may reducecases in which the UE cannot transmit per beam group or per TRP BFRrequests, thus reducing delays in beam failure recover, decreasinglatency of uplink and/or downlink traffic, and increasing network speed.Furthermore, the UE may select the uplink resource based at least inpart on a determination of an earliest available network resource, whichmay decrease latency associated with requesting BFR.

FIG. 7 is a diagram illustrating an example 700 associated with BFRrequests for per beam group BFR, in accordance with the presentdisclosure. As shown in FIG. 7, example 700 includes communicationbetween a UE 120, a first TRP 705-1, and a second TRP 705-2. In someaspects, the first TRP 705-1, the second TRP 705-2, and UE 120 may beincluded in a wireless network, such as wireless network 100. The UE 120may communicate with the first TRP 705-1 and the second TRP 705-2 viawireless access links, which may include uplinks and downlinks.

The first TRP 705-1 and the second TRP 705-2 (collectively, TRPs 705)may correspond to TRPs described elsewhere herein, such as TRPs 535described above in connection with FIG. 5 and/or TRPs 605 describedabove in connection with FIG. 6. The TRPs 705 may communicate with eachother and may coordinate communications with the UE 120 via an interfacebetween the TRPs 705 (e.g., a backhaul interface and/or an access nodecontroller). The TRPs 705 may be in the same cell. For example, the TRPs705 may be DUs associated with the same 5G access node (e.g., gNB). Insome aspects, the TRPs 705 may be co-located at the same base station110. For example, the TRPs 705 may be different antenna arrays or panelsof the same base station 110. In some aspects, the TRPs 705 may belocated at different base station 110 in the same cell. The TRPs 705 maybe associated with different beam groups in the cell. For example, afirst beam group in the cell may be associated with the first TRP 705-1and a second beam group in the cell may be associated with the secondTRP 705-2.

As shown in FIG. 7, and by reference number 710, the UE 120 may receive,from the first TRP 705-1, a first BFD reference signal set associatedwith the first beam group, and the UE 120 may receive, from the secondTRP 705-2, a second BFD reference signal set associated with the secondbeam group. Each BFD reference signal set (e.g., the first BFD referencesignal set and the second BFD reference signal set) may include one ormore reference signals (e.g., CSI-RSs and/or SSBs) that are periodicallytransmitted to the UE 120.

As further shown in FIG. 7, and by reference number 715, the UE 120 maydetect beam failure for the first beam group. The UE 120 may monitor thefirst BFD reference signal set and the second BFD reference signal setand perform measurements (e.g., RSRP measurements) on the first BFDreference signal set and the second BFD reference signal set as thefirst and second BFD reference signal sets are periodically transmittedto the UE 120. The UE 120 may compare the measurements (e.g., RSRPmeasurements) on the first BFD reference signal set and the second BFDreference signal set with a threshold (Qout). The UE 120 may detect abeam failure indication for the first beam group (e.g., for the firstTRP 705-1) based at least in part on the measurements (e.g., RSRPmeasurements) for an occurrence of the first BFD reference signal setbeing below Qout. The UE 120 may detect a beam failure indication forthe second beam group (e.g., for the second TRP 705-2) based at least inpart on the measurements (e.g., RSRP measurements) for an occurrence ofthe second BFD reference signal set being below Qout. The UE 120 maydetect beam failure for the first beam group (e.g., for the first TRP705-1) based at least in part on detecting more than a threshold numberof beam failure indications in a time duration associated with a BFDtimer.

As further shown in FIG. 7, and by reference number 720, the UE 120 maydetermine an availability of uplink resources in the second beam groupfor a per beam group BFR request based at least in part on detectingbeam failure for the first beam group. In some aspects, the UE 120 maydetermine whether one or more PUCCH scheduling request resources areavailable for transmitting a BFR scheduling request on a beam in thesecond beam group, and/or the UE 120 may determine whether one or morePUSCH resources are available for transmitting a BFR MAC-CE on a beam inthe second beam group.

In some aspects, the UE 120 may determine whether a PUCCH schedulingrequest resource dedicated to per beam group (e.g., per TRP) BFRscheduling requests is configured in the second beam group. In someaspects, the UE 120 may receive (e.g., prior to detecting beam failurefor the first beam set), configuration information that configures oneor more PUCCH scheduling request resources dedicated to per beam groupBFR scheduling requests. For example, the UE 120 may receive theconfiguration information in an RRC message from the first TRP 705-1 orthe second TRP 705-2. In some aspects, the configuration information mayconfigure a dedicated PUCCH scheduling resource in each of the first andsecond beam groups. For example, the configuration information mayinclude a mapping of a PUCCH scheduling request dedicated to BFR for thefirst beam group (e.g., BFR for the first TRP 705-1) to a beam of thesecond beam group (e.g., a beam associated with the second TRP 705-2).The configuration may further include a mapping of a PUCCH schedulingrequest dedicated to BFR for the second beam group (e.g., BFR for thesecond TRP 705-2) to a beam of the first beam group (e.g., a beamassociated with the first TRP 705-1). In some aspects, the configurationinformation may configure a single PUCCH scheduling request resourcededicated to per beam group BFR in the first beam group or the secondbeam group. In some aspects, no PUCCH scheduling request resourcesdedicated to per beam group BFR may be configured in either the firstbeam group or the second beam group.

In some aspects, the UE 120 may determine whether one or more PUCCHscheduling request resources, including PUCCH scheduling requestresources that are not dedicated to per beam group BFR, are available inthe second beam group. For example, the UE 120 may determine whether atleast one PUCCH scheduling request resource is available that isconfigured to use at least a beam associated with the working TRP (e.g.,the second TRP 705-2). In this case, a PUCCH scheduling request resourceconfigured to use at least a beam in the second beam group may bedetermined to be available based at least in part on a determinationthat the PUCCH scheduling request resource does not collide with asemi-persistent downlink symbol configured via RRC signaling, or adynamic downlink symbol indicated by an slot frame indication (SFI).

In some aspects, the UE 120 may determine whether an existing scheduledPUSCH resource is available in the second beam group. For example, theexisting scheduled PUSCH resource may be a grant-free PUSCH resourcethat is periodically scheduled in the second beam group for the UE 120.In some aspects, the UE 120 may determine whether an existing scheduledPUSCH resource (e.g., a grant free PUSCH resource) is available that isconfigured to use a TCI state and/or spatial relationship informationassociated with the working TRP (e.g., the second TRP 705-2). In someaspects, the UE 120 may determine whether an existing scheduled PUSCHresource (e.g., a grant free PUSCH resource) that is large enough toaccommodate a MAC-CE (e.g., the BFR MAC-CE) is available in the secondbeam group. In some aspects, the existing scheduled PUSCH resource maybe configured to be transmitted on any component carrier. In someaspects, the UE 120 may determine whether the existing scheduled PUSCHresource is configured to be transmitted on a Pcell, an PScell, an Scellconfigured with PUCCH, and/or another component carrier configured totransmit a PUCCH scheduling request.

As further shown in FIG. 7, and by reference number 725, the UE 120 maytransmit a BFR request. In some aspects, the UE 120 may selectivelytransmit the BFR request for the first beam group based at least in parton the determination of uplink resource availability in the second beamgroup. The BFR request may refer to the BFR scheduling request (e.g., toschedule an uplink grant for a BFR MAC-CE), the BFR MAC-CE, both the BFRscheduling request and the BFR MAC-CE, and/or a RACH BFR request. The UE120 may select whether to transmit the BFR request and may select whichtype of BFR request to transmit (e.g., the BFR scheduling request, theBFR MAC-CE (without a scheduling request), or the RACH BFR request)based at least in part on the determination of uplink resourceavailability in the second beam group.

In some aspects, the UE 120 may transmit the BFR scheduling request on abeam in the second beam group using a PUCCH scheduling request resourcededicated to per beam group BFR (e.g., dedicated to BFR for the firstbeam group), based at least in part on a determination that thededicated PUCCH scheduling request is configured on a beam in the secondbeam group.

In some aspects, the UE 120 may transmit the BFR scheduling requestusing an earliest available PUCCH scheduling request resource on a beamof the second beam group, based at least in part on a determination thatone or more PUCCH scheduling resources are available in the second beamgroup. In this case, the earliest available PUCCH scheduling resourcemay be a PUCCH scheduling request resource dedicated to per beam groupBFR or another PUCCH scheduling request resource that is not dedicatedto per beam group BFR.

The earliest available PUCCH scheduling request may use at least a beamassociated with the second beam group (e.g., a beam associated with theworking TRP). In some aspects, the earliest available PUCCH schedulingrequest resource may be associated with a first spatial relationshipassociated with the beam of the second beam group and associated with assecond spatial relationship associated with a beam of the first beamgroup. For example, the PUCCH scheduling request resource may beconfigured with two beams, one beam to be transmitted to the first TRP705-1 and another beam to be transmitted to second TRP 705-2. In someaspects, the UE 120 may only transmit the BFR scheduling request via thebeam associated with the working TRP (e.g., the beam associated with thesecond TRP 705-2). For example, the UE 120 may transmit the BFRscheduling request using the earliest available PUCCH scheduling requestresource on the beam of the second beam group without transmitting theBFR recovery request on the beam of the first beam group. In someaspects, the UE 120 may transmit the BFR scheduling request on all beamsconfigured for the earliest available scheduling request, regardless ofthe failed TRP (e.g., the first TRP 705-1). For example, the UE 120 maytransmit the BFR scheduling request using the earliest available PUCCHscheduling request resource on the beam of the second beam group and onthe beam of the first beam group.

In a case in which the UE 120 transmits the BFR scheduling request usinga PUCCH scheduling request resource, on a beam of the second beam group(e.g., to the second TRP 705-2), the UE 120 may receive, from the secondTRP 705-2, an uplink grant that schedules a PUSCH resource fortransmitting the BFR MAC-CE. The UE 120 may perform candidate beamdetection to select a candidate beam for the first beam group. Forexample, the UE 120 may select the candidate beam based on measurementsperformed on reference signals in a new beam information referencesignal set. The UE 120 may transmit the BFR MAC-CE using the PUSCHresource granted by the uplink grant. For example, the granted PUSCHresource may be scheduled and transmitted on a beam in the second beamgroup (e.g., a beam to the second TRP 705-2) or on a beam in the firstgroup (e.g., a beam to the first TRP 705-1). In some aspects, the BFRMAC-CE may include an indication of the selected candidate beam, such asan index associated with the corresponding reference signal in the newbeam information reference signal set. The BFR MAC-CE may also includean indication of the failed TRP (e.g. the first TRP 705-1), such asindex associated with the failed TRP.

In some aspects, the UE 120 may transmit the BFR MAC-CE using anexisting scheduled PUSCH resource (e.g., a grant free PUSCH resource) ona beam of the second beam group, without transmitting a BFR schedulingrequest, based at least in part on a determination that the existingscheduled PUSCH resource is available and based at least in part on adetermination that a size of the existing scheduled PUSCH resource islarge enough to transmit the BFR MAC-CE. In this case, the existingscheduled PUSCH resource may be a scheduled PUSCH resource that uses aTCI state and/or spatial relationship information associated with a beamin the second beam group associated with working TRP (e.g., the secondTRP 705-2). In some aspects, the UE 120 may select to transmit the BFRMAC-CE using the existing scheduled PUSCH resource based at least inpart on a component carrier associated with the existing scheduled PUSCHresource. For example, the UE 120 may select to transmit the BFR MAC-CEusing the existing scheduled PUSCH resource based at least in part on adetermination that the component carrier is a Pcell, a PScell, an Scellconfigured with PUCCH, and/or another component carrier that isconfigured to transmit PUCCH scheduling requests. In some aspects, theUE 120 may select to transmit the BFR MAC-CE using the existingscheduled PUSCH resource on a component carrier configured for theexisting scheduled PUSCH resource.

In some aspects, the UE 120 may determine that there is no PUCCHscheduling request resource that is dedicated to per beam group BFRconfigured in the second beam group. For example, in this case, theremay be a single dedicated PUCCH scheduling request resource configuredin the first beam group, or there may be no configured dedicated PUCCHscheduling request resources. In some aspects, based at least in part onthe determination that there is no PUCCH scheduling request resourcethat is dedicated to per beam group BFR configured in the second beamgroup, the UE 120 may transmit a BFR scheduling request using anon-dedicated PUCCH scheduling request resource associated with thesecond beam group (based at least in part on a determination that thenon-dedicated PUCCH scheduling request is available), or the UE 120 maytransmit a BFR MAC-CE using an existing scheduled PUSCH associated withthe second beam group (based at least in part on a determination thatthe existing scheduled PUSCH resource is available).

In some aspects, based at least in part on a determination that a singlededicated PUCCH scheduling request resource is configured in the firstbeam group, the UE 120 may transmit a BFR scheduling request using thededicated PUCCH scheduling request resource on a beam in the first beamgroup (e.g., on a beam to the first TRP 705-1), even though the firstbeam group may be associated with the failed TRP. For example, the UE120 may transmit the BFR scheduling request instead or in addition totransmitting the BFR scheduling request and/or the BFR MAC-CE on a beamin the second beam group.

In some aspects, the UE 120 may select an earliest available resourceamong a dedicated PUCCH scheduling resource configured in the secondbeam group, an earliest available non-dedicated PUCCH schedulingresource in the second beam group, and an existing scheduled PUSCHresource in the second beam group. In some aspects, the UE 120 maypredict whether an earliest available PUCCH scheduling request resource(e.g., dedicated or non-dedicated) will result in an earlier scheduledPUSCH resource (via an uplink grant) than an earliest available existingscheduled PUSCH resource. In this case, the UE 120 may select totransmit a BFR scheduling request using the earliest available PUCCHscheduling request resource based at least in part on a prediction thatthe earliest available PUCCH scheduling request resource will result inan earlier scheduled PUSCH resource than the earliest available existingscheduled PUSCH resource. The UE 120 may select to transmit the BFRMAC-CE using the earliest existing scheduled PUSCH resource (withouttransmitting a BFR scheduling request) based at least in part on aprediction that the earliest available PUCCH scheduling request resourcewill not result in an earlier scheduled PUSCH resource than the earliestexisting scheduled PUSCH resource.

In some aspects, the UE 120 may select not to transmit a BFR request forthe first beam group based at least in part on a determination thatthere is no PUCCH scheduling request resource dedicated to per beamgroup BFR configured in the second beam group, based at least in part ona determination that there is no other PUCCH scheduling resourceassociated with the second beam group available, and based at least inpart on a determination that there is no existing scheduled PUSCHresource associated with the second beam group available. In this case,the UE 120 may declare cell level beam failure for the cell based atleast in part on selecting not to transmit the BFR request for the firstbeam group. For example, in this case, the UE 120 may declare cell levelbeam failure even if there is a still working TRP (e.g., the second TRP705-2).

In some aspects, the UE 120 may perform a RACH procedure to transmit theBFR request for the first beam group based at least in part on adetermination that there are no available uplink resources in the secondbeam group for transmitting the beam failure recovery request.

As further shown in FIG. 7, and by reference number 730, the UE 120 mayreceive a BFR response based at least in part on transmitting the BFRrequest. In some aspects, the second TRP 705-2 may transmit the BFRresponse to the UE 120, as shown in FIG. 7. In some aspects, the firstTRP 705-1 may transmit the BFR response to the UE 120.

In some aspects, the BFR response may be a response to a BFR MAC-CE. Inthis case, the BFR response may include an uplink grant that schedules anew transmission (e.g., with a toggled NDI) for the same HARQ process asthe PUSCH communication carrying the BFR MAC-CE. This BFR responseindicates, to the UE 120, to use the selected beam candidate indicatedin the BFR MAC-CE for the communications with the first TRP 705-1. Inthis case, after a number of symbols (e.g., 28 symbols) from an end ofthe BFR response the UE 120 may reset all CORESET beams associated withthe first TRP 705-1 to the selected beam candidate and/or reset PUCCHbeams associated with the first TRP 705-1 to the selected beamcandidate.

In some aspects, the BFR response may be a random access response to aRACH BFR request. In a case in which the RACH BFR request is transmittedusing a selected candidate beam of the first beam group, the BFRresponse may indicate, to the UE 120, to use a selected beam candidatefor communications with the first TRP 705-1. In a case in which the RACHBFR request is transmitted on a beam of the second beam group, the BFRresponse may include an uplink grant for the UE 120 to transmit a MAC-CE(e.g., BFR MAC-CE) that includes an indication of the selected candidatebeam.

As described above in connection with FIG. 7, the UE 120 may detect beamfailure for the first beam group. The UE 120 may selectively transmit aBFR request for the first beam group based at least in part on adetermination of uplink resource availability in the second beam group.The first beam group may be associated with the first TRP 705-1 and thesecond beam group may be associated with the second TRP 705-2. In someaspects, based at least in part on the determination of the uplinkresource availability in the second beam group, the UE 120 may transmita BFR scheduling request on a beam of the second beam group using aPUCCH scheduling request resource dedicated to BFR for the first beamgroup, the UE 120 may transmit a BFR scheduling request using anearliest available PUCCH scheduling request resource on a beam of thesecond beam group, or the UE 120 may transmit a BFR MAC-CE using anexisting scheduled PUSCH resource on a beam of the second beam group. Asa result, the UE 120 may select an available uplink resource in a casein which there are no dedicated resources configured in the second beamgroup. This may reduce cases in which the UE 120 cannot transmit perbeam group or per TRP BFR requests, thus reducing delays in beam failurerecover, decreasing latency of uplink and/or downlink traffic, andincreasing network speed. Furthermore, the UE 120 may select the uplinkresource based at least in part on a determination of an earliestavailable network resource, which may decrease latency associated withrequesting BFR.

As indicated above, FIG. 7 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 7.

FIG. 8 is a diagram illustrating an example 800 associated with BFRrequests for per beam group BFR, in accordance with the presentdisclosure. As shown in FIG. 8, example 800 includes communicationbetween a UE 120, a first TRP 705-1, and a second TRP 705-2. In someaspects, the first TRP 705-1, the second TRP 705-2, and UE 120 may beincluded in a wireless network, such as wireless network 100. The UE 120may communicate with the first TRP 705-1 and the second TRP 705-2 viawireless access links, which may include uplinks and downlinks.

The first TRP 705-1 and the second TRP 705-2 (collectively, TRPs 705)may correspond to TRPs described elsewhere herein, such as TRPs 535described above in connection with FIG. 5 and/or TRPs 605 describedabove in connection with FIG. 6. The TRPs 705 may communicate with eachother and may coordinate communications with the UE 120 via an interfacebetween the TRPs 705 (e.g., a backhaul interface and/or an access nodecontroller). The TRPs 705 may be in the same cell. For example, the TRPs705 may be DUs associated with the same 5G access node (e.g., gNB). Insome aspects, the TRPs 705 may be co-located at the same base station110. For example, the TRPs 705 may be different antenna arrays or panelsof the same base station 110. In some aspects, the TRPs 705 may belocated at different base station 110 in the same cell. The TRPs 705 maybe associated with different beam groups in the cell. For example, afirst beam group in the cell may be associated with the first TRP 705-1and a second beam group in the cell may be associated with the secondTRP 705-2.

As shown in FIG. 8, and by reference number 805, the UE 120 may receive,from the first TRP 705-1, a first BFD reference signal set associatedwith the first beam group, and the UE 120 may receive, from the secondTRP 705-2, a second BFD reference signal set associated with the secondbeam group. Each BFD reference signal set (e.g., the first BFD referencesignal set and the second BFD reference signal set) may include one ormore reference signals (e.g., CSI-RSs and/or SSBs) that are periodicallytransmitted to the UE 120.

As further shown in FIG. 8, and by reference number 810, the UE 120 maydetect beam failure for the first beam group. The UE 120 may monitor thefirst BFD reference signal set and the second BFD reference signal setand perform measurements (e.g., RSRP measurements) on the first BFDreference signal set and the second BFD reference signal set as thefirst and second BFD reference signal sets are periodically transmittedto the UE 120. The UE 120 may compare the measurements (e.g., RSRPmeasurements) on the first BFD reference signal set and the second BFDreference signal set with a threshold (Qout). The UE 120 may detect abeam failure indication for the first beam group (e.g., for the firstTRP 705-1) based at least in part on the measurements (e.g., RSRPmeasurements) for an occurrence of the first BFD reference signal setbeing below Qout. The UE 120 may detect a beam failure indication forthe second beam group (e.g., for the second TRP 705-2) based at least inpart on the measurements (e.g., RSRP measurements) for an occurrence ofthe second BFD reference signal set being below Qout. The UE 120 maydetect beam failure for the first beam group (e.g., for the first TRP705-1) based at least in part on detecting more than a threshold numberof beam failure indications in a time duration associated with a BFDtimer.

As further shown in FIG. 8, and by reference number 815, the UE 120 maydetermine an availability of uplink resources in the second beam groupfor a per beam group BFR request based at least in part on detectingbeam failure for the first beam group. In some aspects, such as inexample 800 of FIG. 8, the UE 120 may determine that one or more PUCCHscheduling request resources are available for transmitting a BFRscheduling request on a beam in the second beam group. For example, theone or more available PUCCH scheduling request resources may include aPUCCH scheduling request resource dedicated to per beam group (e.g., perTRP) BFR configured on a beam of the second beam group and/or one ormore available non-dedicated PUCCH scheduling request resources in thesecond beam group.

As further shown in FIG. 8, and by reference number 820, the UE 120 maytransmit a BFR scheduling request using a dedicated or other availablePUCCH scheduling request resource in the second beam group. In someaspects, the UE 120 may select to transmit the BFR scheduling requestusing the PUCCH scheduling request resource in the second beam groupbased at least in part on the determination of uplink resourceavailability in the second beam group.

In some aspects, the UE 120 may transmit the BFR scheduling request on abeam in the second beam group using a PUCCH scheduling request resourcededicated to per beam group BFR (e.g., dedicated to BFR for the firstbeam group), based at least in part on a determination that thededicated PUCCH scheduling request is configured on a beam in the secondbeam group.

In some aspects, the UE 120 may transmit the BFR scheduling requestusing an earliest available PUCCH scheduling request resource on a beamof the second beam group, based at least in part on a determination thatone or more PUCCH scheduling resources are available in the second beamgroup. In this case, the earliest available PUCCH scheduling resourcemay be a PUCCH scheduling request resource dedicated to per beam groupBFR or another PUCCH scheduling request resource that is not dedicatedto per beam group BFR.

The earliest available PUCCH scheduling request may use at least a beamassociated with the second beam group (e.g., a beam associated with theworking TRP). In some aspects, the earliest available PUCCH schedulingrequest resource may be associated with a first spatial relationshipassociated with the beam of the second beam group and associated with assecond spatial relationship associated with a beam of the first beamgroup. For example, the PUCCH scheduling request resource may beconfigured with two beams, one beam to be transmitted to the first TRP705-1 and another beam to be transmitted to second TRP 705-2. In someaspects, the UE 120 may only transmit the BFR scheduling request via thebeam associated with the working TRP (e.g., the beam associated with thesecond TRP 705-2). For example, the UE 120 may transmit the BFRscheduling request using the earliest available PUCCH scheduling requestresource on the beam of the second beam group without transmitting theBFR recovery request on the beam of the first beam group. In someaspects, the UE 120 may transmit the BFR scheduling request on all beamsconfigured for the earliest available scheduling request, regardless ofthe failed TRP (e.g., the first TRP 705-1). For example, the UE 120 maytransmit the BFR scheduling request using the earliest available PUCCHscheduling request resource on the beam of the second beam group and onthe beam of the first beam group.

In some aspects, the UE 120 may transmit the BFR scheduling requestusing a non-dedicated PUCCH scheduling request resource associated withthe second beam group based at least in part on a determination that thenon-dedicated PUCCH scheduling request is available and based at leastin part on a determination that that there is no PUCCH schedulingrequest resource that is dedicated to per beam group BFR configured inthe second beam group. For example, in this case, there may be a singlededicated PUCCH scheduling request resource configured in the first beamgroup, or there may be no configured dedicated PUCCH scheduling requestresources.

In some aspects, the UE 120 may transmit the BFR scheduling request onan earliest available PUCCH scheduling request resource (e.g., dedicatedor non-dedicated PUCCH scheduling request resource) associated with thesecond beam group based at least in part on a determination that theearliest available PUCCH scheduling request resource is an earliestavailable resource among a dedicated PUCCH scheduling resourceconfigured in the second beam group, an earliest available non-dedicatedPUCCH scheduling resource in the second beam group, and an existingscheduled PUSCH resource in the second beam group. In some aspects, theUE 120 may select to transmit the BFR scheduling request using theearliest available PUCCH scheduling request resource based at least inpart on a prediction that the earliest available PUCCH schedulingrequest resource will result in an earlier scheduled PUSCH resource thanan earliest available existing scheduled PUSCH resource.

As further shown in FIG. 8, and by reference number 825, the UE 120 mayreceive, from the second TRP 705-2, an uplink grant based at least in apart on transmitting the BFR scheduling request to the second TRP 705-2on a beam in the second beam group. The uplink grant may schedule aPUSCH resource for transmitting a BFR MAC-CE.

As further shown in FIG. 8, and by reference number 830, the UE 120 maytransmit the BFR MAC-CE using the scheduled PUSCH resource granted bythe uplink grant. The UE 120 may perform candidate beam detection toselect a candidate beam for the first beam group. For example, the UE120 may select the candidate beam based on measurements performed onreference signals in a new beam information reference signal set. Insome aspects, the BFR MAC-CE may include an indication of the selectedcandidate beam, such as an index associated with the correspondingreference signal in the new beam information reference signal set. Insome aspects, the BFR MAC-CE may also include an indication of thefailed TRP (e.g. the first TRP 705-1), such as index associated with thefailed TRP. In some aspects, the granted PUSCH resource may be scheduledon a beam in the second beam group (e.g., a beam to the second TRP705-2). In this case, as shown in FIG. 8, the UE 120 may transmit theBFR MAC-CE to the second TRP 705-2 on the beam in the second beam group.In some aspects, the granted PUSCH resource may be scheduled on a beamin the first group (e.g., a beam to the first TRP 705-1). In this case,the UE 120 may transmit the BFR MAC-CE to the first TRP 705-1 on thebeam in the first beam group.

As further shown in FIG. 8, and by reference number 835, the UE 120 mayreceive a BFR response based at least in part on transmitting the BFRMAC-CE. In some aspects, the second TRP 705-2 may transmit the BFRresponse to the UE 120, as shown in FIG. 8. In some aspects, the firstTRP 705-1 may transmit the BFR response to the UE 120. In some aspects,the BFR response may be a response to the BFR MAC-CE. In this case, theBFR response may include an uplink grant that schedules a newtransmission (e.g., with a toggled NDI) for the same HARQ process as thePUSCH communication carrying the BFR MAC-CE. This BFR responseindicates, to the UE 120, to use the selected beam candidate indicatedin the BFR MAC-CE for the communications with the first TRP 705-1. Inthis case, after a number of symbols (e.g., 28 symbols) from an end ofthe BFR response the UE 120 may reset all CORESET beams associated withthe first TRP 705-1 to the selected beam candidate and/or reset PUCCHbeams associated with the first TRP 705-1 to the selected beamcandidate.

As indicated above, FIG. 8 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 8.

FIG. 9 is a diagram illustrating an example 900 associated with BFRrequests for per beam group BFR, in accordance with the presentdisclosure. As shown in FIG. 9, example 900 includes communicationbetween a UE 120, a first TRP 705-1, and a second TRP 705-2. In someaspects, the first TRP 705-1, the second TRP 705-2, and UE 120 may beincluded in a wireless network, such as wireless network 100. The UE 120may communicate with the first TRP 705-1 and the second TRP 705-2 viawireless access links, which may include uplinks and downlinks.

The first TRP 705-1 and the second TRP 705-2 (collectively, TRPs 705)may correspond to TRPs described elsewhere herein, such as TRPs 535described above in connection with FIG. 5 and/or TRPs 605 describedabove in connection with FIG. 6. The TRPs 705 may communicate with eachother and may coordinate communications with the UE 120 via an interfacebetween the TRPs 705 (e.g., a backhaul interface and/or an access nodecontroller). The TRPs 705 may be in the same cell. For example, the TRPs705 may be DUs associated with the same 5G access node (e.g., gNB). Insome aspects, the TRPs 705 may be co-located at the same base station110. For example, the TRPs 705 may be different antenna arrays or panelsof the same base station 110. In some aspects, the TRPs 705 may belocated at different base station 110 in the same cell. The TRPs 705 maybe associated with different beam groups in the cell. For example, afirst beam group in the cell may be associated with the first TRP 705-1and a second beam group in the cell may be associated with the secondTRP 705-2.

As shown in FIG. 9, and by reference number 905, the UE 120 may receive,from the first TRP 705-1, a first BFD reference signal set associatedwith the first beam group, and the UE 120 may receive, from the secondTRP 705-2, a second BFD reference signal set associated with the secondbeam group. Each BFD reference signal set (e.g., the first BFD referencesignal set and the second BFD reference signal set) may include one ormore reference signals (e.g., CSI-RSs and/or SSBs) that are periodicallytransmitted to the UE 120.

As further shown in FIG. 9, and by reference number 910, the UE 120 maydetect beam failure for the first beam group. The UE 120 may monitor thefirst BFD reference signal set and the second BFD reference signal setand perform measurements (e.g., RSRP measurements) on the first BFDreference signal set and the second BFD reference signal set as thefirst and second BFD reference signal sets are periodically transmittedto the UE 120. The UE 120 may compare the measurements (e.g., RSRPmeasurements) on the first BFD reference signal set and the second BFDreference signal set with a threshold (Qout). The UE 120 may detect abeam failure indication for the first beam group (e.g., for the firstTRP 705-1) based at least in part on the measurements (e.g., RSRPmeasurements) for an occurrence of the first BFD reference signal setbeing below Qout. The UE 120 may detect a beam failure indication forthe second beam group (e.g., for the second TRP 705-2) based at least inpart on the measurements (e.g., RSRP measurements) for an occurrence ofthe second BFD reference signal set being below Qout. The UE 120 maydetect beam failure for the first beam group (e.g., for the first TRP705-1) based at least in part on detecting more than a threshold numberof beam failure indications in a time duration associated with a BFDtimer.

As further shown in FIG. 9, and by reference number 915, the UE 120 maydetermine an availability of uplink resources in the second beam groupfor a per beam group BFR request based at least in part on detectingbeam failure for the first beam group. In some aspects, such as inexample 900 of FIG. 9, the UE 120 may determine that an existingscheduled PUSCH resource is available in the second beam group. Forexample, the existing scheduled PUSCH resource may be a grant-free PUSCHresource that is periodically scheduled in the second beam group for theUE 120.

In some aspects, the UE 120 may determine that an existing scheduledPUSCH resource (e.g., a grant free PUSCH resource) is available that isconfigured to use a TCI state and/or spatial relationship informationassociated with the working TRP (e.g., the second TRP 705-2). In someaspects, the UE 120 may determine that an existing scheduled PUSCHresource (e.g., a grant free PUSCH resource) that is large enough toaccommodate a MAC-CE (e.g., the BFR MAC-CE) is available in the secondbeam group. In some aspects, the existing scheduled PUSCH resource maybe configured to be transmitted on any component carrier. In someaspects, the UE 120 may determine whether the existing scheduled PUSCHresource is configured to be transmitted on a Pcell, an PScell, an Scellconfigured with PUCCH, and/or another component carrier configured totransmit a PUCCH scheduling request.

As further shown in FIG. 9, and by reference number 920, the UE 120 maytransmit a BFR MAC-CE using the available existing PUSCH resource in thesecond beam group. For example, the UE 120 may transmit the BFR MAC-CEto the second TRP 705-2 on a beam of the second beam group using theavailable existing PUSCH. In some aspects, the UE 120 may select totransmit the BFR MAC-CE using the available existing PUSCH resource inthe second beam group based at least in part on the determination ofuplink resource availability in the second beam group.

In some aspects, the UE 120 may transmit the BFR MAC-CE using theexisting scheduled PUSCH resource (e.g., a grant free PUSCH resource) ona beam of the second beam group, without transmitting a BFR schedulingrequest, based at least in part on a determination that the existingscheduled PUSCH resource is available and based at least in part on adetermination that a size of the existing scheduled PUSCH resource islarge enough to transmit the BFR MAC-CE. In this case, the existingscheduled PUSCH resource may be a scheduled PUSCH resource that uses aTCI state and/or spatial relationship information associated with a beamin the second beam group associated with working TRP (e.g., the secondTRP 705-2). In some aspects, the UE 120 may select to transmit the BFRMAC-CE using the existing scheduled PUSCH resource based at least inpart on a component carrier associated with the existing scheduled PUSCHresource. For example, the UE 120 may select to transmit the BFR MAC-CEusing the existing scheduled PUSCH resource based at least in part on adetermination that the component carrier is a Pcell, a PScell, an Scellconfigured with PUCCH, and/or another component carrier that isconfigured to transmit PUCCH scheduling requests. In some aspects, theUE 120 may select to transmit the BFR MAC-CE using the existingscheduled PUSCH resource on a component carrier configured for theexisting scheduled PUSCH resource.

In some aspects, the UE 120 may transmit the BFR MAC-CE using theexisting scheduled PUSCH resource in the second beam group based atleast in part on a determination that the existing scheduled PUSCHresource is available and based at least in part on a determination thatthere is no PUCCH scheduling request resource that is dedicated to perbeam group BFR configured in the second beam group. For example, in thiscase, there may be a single dedicated PUCCH scheduling request resourceconfigured in the first beam group, or there may be no configureddedicated PUCCH scheduling request resources.

In some aspects, the UE 120 may transmit the BFR MAC-CE using theexisting scheduled PUSCH resource in the second beam group based atleast in part on a determination that the existing scheduled PUSCHresource is an earliest available resource among a dedicated PUCCHscheduling resource configured in the second beam group, an earliestavailable non-dedicated PUCCH scheduling resource in the second beamgroup, and the existing scheduled PUSCH resource in the second beamgroup. In some aspects, the UE 120 may select to transmit the BFR MAC-CEusing the existing scheduled PUSCH resource (without transmitting a BFRscheduling request) based at least in part on a prediction that theearliest available PUCCH scheduling request resource in the second beamgroup will not result in an earlier scheduled PUSCH resource than theexisting scheduled PUSCH resource.

The UE 120 may perform candidate beam detection to select a candidatebeam for the first beam group. For example, the UE 120 may select thecandidate beam based on measurements performed on reference signals in anew beam information reference signal set. In some aspects, the BFRMAC-CE may include an indication of the selected candidate beam, such asan index associated with the corresponding reference signal in the newbeam information reference signal set. In some aspects, the BFR MAC-CEmay also include an indication of the failed TRP (e.g. the first TRP705-1), such as index associated with the failed TRP.

As further shown in FIG. 9, and by reference number 925, the UE 120 mayreceive a BFR response based at least in part on transmitting the BFRMAC-CE. For example, the second TRP 705-2 may transmit the BFR responseto the UE 120 based at least in part on receiving the BFR MAC-CE. Insome aspects, the BFR response may be a response to the BFR MAC-CE. Inthis case, the BFR response may include an uplink grant that schedules anew transmission (e.g., with a toggled NDI) for the same HARQ process asthe PUSCH communication carrying the BFR MAC-CE. This BFR responseindicates, to the UE 120, to use the selected beam candidate indicatedin the BFR MAC-CE for the communications with the first TRP 705-1. Inthis case, after a number of symbols (e.g., 28 symbols) from an end ofthe BFR response the UE 120 may reset all CORESET beams associated withthe first TRP 705-1 to the selected beam candidate and/or reset PUCCHbeams associated with the first TRP 705-1 to the selected beamcandidate.

As indicated above, FIG. 9 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 9.

FIG. 10 is a diagram illustrating an example 1000 associated with BFRrequests for per beam group BFR, in accordance with the presentdisclosure. As shown in FIG. 10, example 1000 includes communicationbetween a UE 120, a first TRP 705-1, and a second TRP 705-2. In someaspects, the first TRP 705-1, the second TRP 705-2, and UE 120 may beincluded in a wireless network, such as wireless network 100. The UE 120may communicate with the first TRP 705-1 and the second TRP 705-2 viawireless access links, which may include uplinks and downlinks.

The first TRP 705-1 and the second TRP 705-2 (collectively, TRPs 705)may correspond to TRPs described elsewhere herein, such as TRPs 535described above in connection with FIG. 5 and/or TRPs 605 describedabove in connection with FIG. 6. The TRPs 705 may communicate with eachother and may coordinate communications with the UE 120 via an interfacebetween the TRPs 705 (e.g., a backhaul interface and/or an access nodecontroller). The TRPs 705 may be in the same cell. For example, the TRPs705 may be DUs associated with the same 5G access node (e.g., gNB). Insome aspects, the TRPs 705 may be co-located at the same base station110. For example, the TRPs 705 may be different antenna arrays or panelsof the same base station 110. In some aspects, the TRPs 705 may belocated at different base station 110 in the same cell. The TRPs 705 maybe associated with different beam groups in the cell. For example, afirst beam group in the cell may be associated with the first TRP 705-1and a second beam group in the cell may be associated with the secondTRP 705-2.

As shown in FIG. 10, and by reference number 1005, the UE 120 mayreceive, from the first TRP 705-1, a first BFD reference signal setassociated with the first beam group, and the UE 120 may receive, fromthe second TRP 705-2, a second BFD reference signal set associated withthe second beam group. Each BFD reference signal set (e.g., the firstBFD reference signal set and the second BFD reference signal set) mayinclude one or more reference signals (e.g., CSI-RSs and/or SSBs) thatare periodically transmitted to the UE 120.

As further shown in FIG. 10, and by reference number 1010, the UE 120may detect beam failure for the first beam group. The UE 120 may monitorthe first BFD reference signal set and the second BFD reference signalset and perform measurements (e.g., RSRP measurements) on the first BFDreference signal set and the second BFD reference signal set as thefirst and second BFD reference signal sets are periodically transmittedto the UE 120. The UE 120 may compare the measurements (e.g., RSRPmeasurements) on the first BFD reference signal set and the second BFDreference signal set with a threshold (Qout). The UE 120 may detect abeam failure indication for the first beam group (e.g., for the firstTRP 705-1) based at least in part on the measurements (e.g., RSRPmeasurements) for an occurrence of the first BFD reference signal setbeing below Qout. The UE 120 may detect a beam failure indication forthe second beam group (e.g., for the second TRP 705-2) based at least inpart on the measurements (e.g., RSRP measurements) for an occurrence ofthe second BFD reference signal set being below Qout. The UE 120 maydetect beam failure for the first beam group (e.g., for the first TRP705-1) based at least in part on detecting more than a threshold numberof beam failure indications in a time duration associated with a BFDtimer.

As further shown in FIG. 10, and by reference number 1015, the UE 120may determine that no uplink resources are available in the second beamset for transmitting a BFR request for the first beam set. For example,the UE 120 may determine that there is no PUCCH scheduling requestresource dedicated to per beam group BFR configured in the second beamgroup, there is no other PUCCH scheduling resource associated with thesecond beam group available, and there is no existing scheduled PUSCHresource associated with the second beam group available.

As further shown in FIG. 10, and by reference number 1020, in someaspects, the UE 120 may declare cell level beam failure for the cellbased at least in part on the determination that no uplink resources areavailable in the second beam set for transmitting a BFR request for thefirst beam set. In this case, the UE 120 may select not to transmit aBFR request for the first beam group. For example, the UE 120 may selectnot to transmit a BFR request based at least in part on a determinationthat there is no PUCCH scheduling request resource dedicated to per beamgroup BFR configured in the second beam group, based at least in part ona determination that there is no other PUCCH scheduling resourceassociated with the second beam group available, and based at least inpart on a determination that there is no existing scheduled PUSCHresource associated with the second beam group available. In this case,the UE 120 may declare cell level beam failure for the cell even ifthere is a still working TRP (e.g., the second TRP 705-2).

As further shown in FIG. 10, and by reference number 1025, in someaspects, the UE 120 may perform a RACH procedure to transmit the BFRrequest for the first beam group based at least in part on thedetermination that no uplink resources are available in the second beamset for transmitting a BFR request for the first beam set. In someaspects, the UE 120 may select to perform the RACH procedure, based atleast in part on the determination that no uplink resources areavailable in the second beam set for transmitting a BFR request for thefirst beam set, instead of declaring cell-level beam failure.

In some aspects, the UE 120 may initiate a contention free RACHprocedure using a RACH configured for the first beam group. For example,a first RACH preamble may be associated with the first beam group (e.g.,the first TRP 705-1) and a second RACH preamble may be configured forthe second beam group (e.g., the second TRP 705-2). In this case, the UE120 may initiate the contention free RACH using a RACH resourceassociated with the first preamble (e.g., the RACH preamble associatedwith the failed TRP).

In some aspects, the UE 120 may initiate the contention free RACHprocedure on selected candidate beam of the first beam group. Forexample, the selected candidate beam may be a candidate replacement beamfor BFR for the first beam group. The select candidate beam may beselected by the UE 120 based on reference signals in a new beaminformation reference signal set configure for the first TRP (e.g., thefirst beam group). In some aspects, the UE 120 may initiate thecontention free RACH procedure on a beam of the second beam group. Forexample, a failed TRP (e.g., the first TRP 705-1) may have acorresponding TRP (e.g., the second TRP 705-2) to transmit a RACH BFRrequest.

The UE 120, based at least in part on transmitting the RACH BFR request,may monitor a search space for a RACH response. For example, the UE 120may monitor the search space for a PDCCH with CRC scrambled by C-RNTI orMCS-C-RNTI. In some aspects, the UE 120 may receive the RACH response(e.g., the PDCCH with CRC scrambled by C-RNTI or MCS-C-RNTI). In thiscase, the BFR response may be the RACH response to a RACH BFR request.In a case in which the RACH BFR request is transmitted using theselected candidate beam of the first beam group, the BFR response mayindicate, to the UE 120, to use a selected beam candidate forcommunications with the first TRP 705-1. In a case in which the RACH BFRrequest is transmitted on a beam of the second beam group, the UE 120may transmit a MAC-CE (e.g., the BFR MAC-CE) that includes an indicationof the selected candidate beam in a subsequent message in the contentionfree RACH procedure. For example, the BFR response may include an uplinkgrant that schedules a PUSCH resource for the UE 120, and the UE 120 maytransmit the BFR MAC-CE using the scheduled PUSCH resource.

In some aspects, the UE 120 may perform a contention based RACHprocedure to transmit the BFR request based at least in part on adetermination that the contention free RACH procedure is unsuccessful.For example, the UE 120 may perform the contention based RACH procedurebased at least in part on the contention free RACH procedure failingmore than a threshold number of times and/or for more than a thresholdamount of time.

In some aspects, in a case in which the per beam group (e.g., per TRP)BFR is not successful after certain number of times or a certain amountof time, the UE 120 may proceed to a cell level BFR procedure or a radiolink failure procedure. For example, the UE 120 may proceed to the celllevel BFR procedure or the radio link failure procedure based at leastin part on the contention based RACH procedure (performed after thecontention free RACH procedure is unsuccessful) failing more than athreshold number of times and/or for more than a threshold amount oftime.

In some aspects, based at least in part on detecting beam failure for abeam group (e.g., detecting beam failure for the first beam groupassociated with the first TRP 705-1), the UE 120 may perform one or moreprocedures (e.g., transmitting a BFR scheduling request and/or a BFRMAC-CE, the contention free RACH procedure, the contention based RACHprocedure, a cell level BFR procedure, and/or a radio link failureprocedure) in an escalating sequence of procedures. In this case, theprocedures may be performed in a particular order, and when BFR fails orcannot be performed using one procedure, the UE 120 may proceed to thenext procedure in the sequence. In some aspects, the order of theprocedures in the sequence may be configured by a base station (e.g.,gNB). In some aspects, the order of the procedures in the sequence maybe preset, for example, in a wireless communication standard.

As indicated above, FIG. 10 is provided as an example. Other examplesmay differ from what is described with respect to FIG. 10.

FIG. 11 is a diagram illustrating an example process 1100 performed, forexample, by a UE, in accordance with the present disclosure. Exampleprocess 1100 is an example where the UE (e.g., UE 120) performsoperations associated with BFR requests for per beam group BFR.

As shown in FIG. 11, in some aspects, process 1100 may include detectingbeam failure for a first beam group in a cell including the first beamgroup and a second beam group (block 1110). For example, the UE (e.g.,using detection component 1208, depicted in FIG. 12) may detect beamfailure for a first beam group in a cell including the first beam groupand a second beam group, as described above.

As further shown in FIG. 11, in some aspects, process 1100 may includeselectively transmitting a beam failure recovery request for the firstbeam group based at least in part on a determination of uplink resourceavailability in the second beam group (block 1120). For example, the UE(e.g., using transmission component 1204, depicted in FIG. 12) mayselectively transmit a beam failure recovery request for the first beamgroup based at least in part on a determination of uplink resourceavailability in the second beam group, as described above.

Process 1100 may include additional aspects, such as any single aspector any combination of aspects described below and/or in connection withone or more other processes described elsewhere herein.

In a first aspect, the first beam group is associated with a firsttransmit and receive point (TRP) in the cell and the second beam groupis associated with a second TRP in the cell.

In a second aspect, alone or in combination with the first aspect,process 1100 includes measuring a first beam failure detection referencesignal set associated with the first beam failure group and a secondbeam failure detection reference signal set associated with the secondbeam failure group, and detecting the beam failure for the first beamgroup is based at least in part on measuring the first beam failuredetection reference signal set.

In a third aspect, alone or in combination with one or more of the firstand second aspects, selectively transmitting the beam failure recoveryrequest for the first beam group includes selecting to transmit the beamfailure recovery request for first the first beam group based at leastin part on a determination that at least one of a PUCCH schedulingrequest resource or a an existing scheduled PUSCH resource is availablein the second beam group.

In a fourth aspect, alone or in combination with one or more of thefirst through third aspects, the beam failure recovery request includesa beam failure recovery scheduling request, and selectively transmittingthe beam failure recovery request for the first beam group includestransmitting the beam failure recovery scheduling request on a beam ofthe second beam group using a PUCCH scheduling request resourcededicated to beam failure recovery for the first beam group.

In a fifth aspect, alone or in combination with one or more of the firstthrough fourth aspects, process 1100 includes receiving, prior todetecting the beam failure, configuration information that maps thePUCCH scheduling request resource dedicated to beam failure recovery forthe first beam group to the beam of the second beam group.

In a sixth aspect, alone or in combination with one or more of the firstthrough fifth aspects, the configuration information maps a PUCCHscheduling request resource dedicated to beam failure recovery for thesecond beam group to a beam of the first beam group.

In a seventh aspect, alone or in combination with one or more of thefirst through sixth aspects, the beam failure recovery request includesa beam failure recovery scheduling request, and selectively transmittingthe beam failure recovery request for the first beam group includestransmitting the beam failure recovery scheduling request using anearliest available physical uplink control channel (PUCCH) schedulingrequest resource on a beam of the second beam group based at least inpart on a determination that one or more PUCCH scheduling requestresources are available in the second beam group.

In an eighth aspect, alone or in combination with one or more of thefirst through seventh aspects, the earliest available PUCCH schedulingrequest resource is configured with a first spatial relationshipassociated with the beam of the second beam group and a second spatialrelationship associated with a beam of the first beam group, andtransmitting the beam failure recovery scheduling request includestransmitting the beam failure recovery scheduling request using theearliest available PUCCH scheduling request resource on the beam of thesecond beam group without transmitting the beam failure recovery requeston the beam of the first beam group.

In a ninth aspect, alone or in combination with one or more of the firstthrough seventh aspects, the earliest available PUCCH scheduling requestresource is configured with a first spatial relationship associated withthe beam of the second beam group and a second spatial relationshipassociated with a beam of the first beam group, and transmitting thebeam failure recovery scheduling request includes transmitting the beamfailure recovery scheduling request using the earliest available PUCCHscheduling request resource on the beam of the second beam group and onthe beam of the first beam group.

In a tenth aspect, alone or in combination with one or more of the firstthrough third aspects, the beam failure recovery request includes a beamfailure recovery MAC-CE, and selectively transmitting the beam failurerecovery request for the first beam group includes transmitting the beamfailure recovery MAC-CE using an existing scheduled PUSCH resource on abeam of the second beam group, without transmitting a beam failurerecovery scheduling request, based at least in part on a determinationthat the existing scheduled PUSCH resource is available and based atleast in part on a determination that a size of the existing scheduledPUSCH resource is large enough to transmit the beam failure recoveryMAC-CE.

In an eleventh aspect, alone or in combination with the tenth aspect,transmitting the beam failure recovery MAC-CE using the existingscheduled PUSCH resource on the beam of the second beam group is furtherbased at least in part on a component carrier associated with theexisting scheduled PUSCH resource.

In a twelfth aspect, alone or in combination with one or more of thefirst through eleventh aspects, selectively transmitting the beamfailure recovery request for the first beam group includes transmitting,based at least in part on a determination that there is no PUCCHscheduling request resource dedicated to beam group beam failurerecovery configured in the second beam group, one of a beam failurerecovery scheduling request using a non-dedicated PUCCH schedulingrequest resource associated with the second beam group, based at leastin part on a determination that the non-dedicated PUCCH schedulingrequest is available, or a beam failure recovery MAC-CE using anexisting scheduled PUSCH resource associated with the second beam group,based at least in part on a determination that the existing scheduledPUSCH resource is available.

In a thirteenth aspect, alone or in combination with one or more of thefirst through third aspects, selectively transmitting the beam failurerecovery request for the first beam group includes selecting not totransmit the beam failure recovery request for the first beam groupbased at least in part on a determination that there is no PUCCHscheduling request resource dedicated to beam group beam failurerecovery configured in the second beam group, based at least in part ona determination that there is no other PUCCH scheduling resourceassociated with the second beam group available, and based at least inpart on a determination that there is no existing scheduled PUSCHresource associated with the second beam group available, and process1100 further includes declaring cell level beam failure for the cellbased at least in part on selecting not to transmit the beam failurerecovery request for the first beam group.

In a fourteenth aspect, alone or in combination with one or more of thefirst through third aspects, selectively transmitting the beam failurerecovery request for the first beam group includes selecting to performa RACH procedure to transmit the beam failure recovery request for thefirst beam group, based at least in part on a determination that thereare no available uplink resources in the second beam group fortransmitting the beam failure recovery request for the first beam group.

In a fifteenth aspect, alone or in combination with the fourteenthaspect, a first RACH preamble is associated with the first beam groupand a second RACH preamble is associated with the second beam group, andperforming the RACH procedure to transmit the beam failure recoveryrequest for the first beam group includes initiating a contention freeRACH procedure using a RACH resource associated with the first RACHpreamble.

In a sixteenth aspect, alone or in combination the fifteenth aspect,initiating the contention free RACH procedure includes initiating thecontention free RACH procedure on a beam of the first beam group, andthe beam of the first beam group is a candidate replacement beam forbeam failure recovery for the first beam group.

In a seventeenth aspect, alone or in combination with the fifteenthaspect, initiating the contention free RACH procedure includesinitiating the contention free RACH procedure on a beam of the secondbeam group.

Although FIG. 11 shows example blocks of process 1100, in some aspects,process 1100 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 11.Additionally, or alternatively, two or more of the blocks of process1100 may be performed in parallel.

FIG. 12 is a block diagram of an example apparatus 1200 for wirelesscommunication. The apparatus 1200 may be a UE, or a UE may include theapparatus 1200. In some aspects, the apparatus 1200 includes a receptioncomponent 1202 and a transmission component 1204, which may be incommunication with one another (for example, via one or more busesand/or one or more other components). As shown, the apparatus 1200 maycommunicate with another apparatus 1206 (such as a UE, a base station,or another wireless communication device) using the reception component1202 and the transmission component 1204. As further shown, theapparatus 1200 may include one or more of a detection component 1208, ameasurement component 1210, or a selection component 1210, among otherexamples.

In some aspects, the apparatus 1200 may be configured to perform one ormore operations described herein in connection with FIGS. 7-10.Additionally, or alternatively, the apparatus 1200 may be configured toperform one or more processes described herein, such as process 1100 ofFIG. 11, or a combination thereof. In some aspects, the apparatus 1200and/or one or more components shown in FIG. 12 may include one or morecomponents of the UE described above in connection with FIG. 2.Additionally, or alternatively, one or more components shown in FIG. 12may be implemented within one or more components described above inconnection with FIG. 2. Additionally, or alternatively, one or morecomponents of the set of components may be implemented at least in partas software stored in a memory. For example, a component (or a portionof a component) may be implemented as instructions or code stored in anon-transitory computer-readable medium and executable by a controlleror a processor to perform the functions or operations of the component.

The reception component 1202 may receive communications, such asreference signals, control information, data communications, or acombination thereof, from the apparatus 1206. The reception component1202 may provide received communications to one or more other componentsof the apparatus 1200. In some aspects, the reception component 1202 mayperform signal processing on the received communications (such asfiltering, amplification, demodulation, analog-to-digital conversion,demultiplexing, deinterleaving, de-mapping, equalization, interferencecancellation, or decoding, among other examples), and may provide theprocessed signals to the one or more other components of the apparatus1206. In some aspects, the reception component 1202 may include one ormore antennas, a demodulator, a MIMO detector, a receive processor, acontroller/processor, a memory, or a combination thereof, of the UEdescribed above in connection with FIG. 2.

The transmission component 1204 may transmit communications, such asreference signals, control information, data communications, or acombination thereof, to the apparatus 1206. In some aspects, one or moreother components of the apparatus 1206 may generate communications andmay provide the generated communications to the transmission component1204 for transmission to the apparatus 1206. In some aspects, thetransmission component 1204 may perform signal processing on thegenerated communications (such as filtering, amplification, modulation,digital-to-analog conversion, multiplexing, interleaving, mapping, orencoding, among other examples), and may transmit the processed signalsto the apparatus 1206. In some aspects, the transmission component 1204may include one or more antennas, a modulator, a transmit MIMOprocessor, a transmit processor, a controller/processor, a memory, or acombination thereof, of the UE described above in connection with FIG.2. In some aspects, the transmission component 1204 may be co-locatedwith the reception component 1202 in a transceiver.

The detection component 1208 may detect beam failure for a first beamgroup in a cell including the first beam group and a second beam group.The selection component 1212 and/or the transmission component 1204 mayselectively transmit a beam failure recovery request for the first beamgroup based at least in part on a determination of uplink resourceavailability in the second beam group.

The measurement component 1210 may measure a first beam failuredetection reference signal set associated with the first beam failuregroup and a second beam failure detection reference signal setassociated with the second beam failure group, wherein detecting thebeam failure for the first beam group is based at least in part onmeasuring the first beam failure detection reference signal set.

The selection component 1212 may select to transmit the beam failurerecovery request for first the first beam group based at least in parton a determination that at least one of a PUCCH scheduling requestresource or a an existing scheduled PUSCH resource is available in thesecond beam group.

The reception component 1202 may receive, prior to detecting the beamfailure, configuration information that maps a PUCCH scheduling requestresource dedicated to beam failure recovery for the first beam group toa beam of the second beam group.

The selection component 1212 may select not to transmit the beam failurerecovery request for the first beam group based at least in part on adetermination that there is no PUCCH scheduling request resourcededicated to beam group beam failure recovery configured in the secondbeam group, based at least in part on a determination that there is noother PUCCH scheduling resource associated with the second beam groupavailable, and based at least in part on a determination that there isno existing scheduled PUSCH resource associated with the second beamgroup available.

The selection component 1212 may select to perform a RACH procedure totransmit the beam failure recovery request for the first beam group,based at least in part on a determination that there are no availableuplink resources in the second beam group for transmitting the beamfailure recovery request for the first beam group.

The number and arrangement of components shown in FIG. 12 are providedas an example. In practice, there may be additional components, fewercomponents, different components, or differently arranged componentsthan those shown in FIG. 12. Furthermore, two or more components shownin FIG. 12 may be implemented within a single component, or a singlecomponent shown in FIG. 12 may be implemented as multiple, distributedcomponents. Additionally, or alternatively, a set of (one or more)components shown in FIG. 12 may perform one or more functions describedas being performed by another set of components shown in FIG. 12.

The following provides an overview of some Aspects of the presentdisclosure:

Aspect 1: A method of wireless communication performed by a userequipment (UE), comprising: detecting beam failure for a first beamgroup in a cell including the first beam group and a second beam group;and selectively transmitting a beam failure recovery request for thefirst beam group based at least in part on a determination of uplinkresource availability in the second beam group.

Aspect 2: The method of Aspect 1, wherein the first beam group isassociated with a first transmit and receive point (TRP) in the cell andthe second beam group is associated with a second TRP in the cell.

Aspect 3: The method of any of Aspects 1-2, further comprising:measuring a first beam failure detection reference signal set associatedwith the first beam failure group and a second beam failure detectionreference signal set associated with the second beam failure group,wherein detecting the beam failure for the first beam group is based atleast in part on measuring the first beam failure detection referencesignal set.

Aspect 4: The method of any of Aspects 1-3, wherein the beam failurerecovery request includes a beam failure recovery scheduling request,and selectively transmitting the beam failure recovery request for thefirst beam group comprises: selecting to transmit the beam failurerecovery request for first the first beam group based at least in parton a determination that at least one of a physical uplink controlchannel (PUCCH) scheduling request resource or a an existing scheduledphysical uplink shared channel (PUSCH) resource is available in thesecond beam group.

Aspect 5: The method of any of Aspects 1-4, wherein the beam failurerecovery request includes a beam failure recovery scheduling request,and selectively transmitting the beam failure recovery request for thefirst beam group comprises: transmitting the beam failure recoveryscheduling request on a beam of the second beam group using a physicaluplink control channel (PUCCH) scheduling request resource dedicated tobeam failure recovery for the first beam group.

Aspect 6: The method of Aspect 5, further comprising: receiving, priorto detecting the beam failure, configuration information that maps thePUCCH scheduling request resource dedicated to beam failure recovery forthe first beam group to the beam of the second beam group.

Aspect 7: The method of Aspect 6, wherein the configuration informationmaps a PUCCH scheduling request resource dedicated to beam failurerecovery for the second beam group to a beam of the first beam group.

Aspect 8: The method of any of Aspects 1-4, wherein the beam failurerecovery request includes a beam failure recovery scheduling request,and selectively transmitting the beam failure recovery request for thefirst beam group comprises: transmitting the beam failure recoveryscheduling request using an earliest available physical uplink controlchannel (PUCCH) scheduling request resource on a beam of the second beamgroup based at least in part on a determination that one or more PUCCHscheduling request resources are available in the second beam group.

Aspect 9: The method of Aspect 8, wherein the earliest available PUCCHscheduling request resource is configured with a first spatialrelationship associated with the beam of the second beam group and asecond spatial relationship associated with a beam of the first beamgroup, and transmitting the beam failure recovery scheduling requestcomprises: transmitting the beam failure recovery scheduling requestusing the earliest available PUCCH scheduling request resource on thebeam of the second beam group without transmitting the beam failurerecovery request on the beam of the first beam group.

Aspect 10: The method of Aspect 8, wherein the earliest available PUCCHscheduling request resource is configured with a first spatialrelationship associated with the beam of the second beam group and asecond spatial relationship associated with a beam of the first beamgroup, and transmitting the beam failure recovery scheduling requestcomprises: transmitting the beam failure recovery scheduling requestusing the earliest available PUCCH scheduling request resource on thebeam of the second beam group and on the beam of the first beam group.

Aspect 11: The method of any of Aspects 1-4, wherein the beam failurerecovery request includes a beam failure recovery medium access control(MAC) control element (MAC-CE), and selectively transmitting the beamfailure recovery request for the first beam group comprises:transmitting the beam failure recovery MAC-CE using an existingscheduled physical uplink shared channel (PUSCH) resource on a beam ofthe second beam group, without transmitting a beam failure recoveryscheduling request, based at least in part on a determination that theexisting scheduled PUSCH resource is available and based at least inpart on a determination that a size of the existing scheduled PUSCHresource is large enough to transmit the beam failure recovery MAC-CE.

Aspect 12: The method of Aspect 11, wherein transmitting the beamfailure recovery MAC-CE using the existing scheduled PUSCH resource onthe beam of the second beam group is further based at least in part on acomponent carrier associated with the existing scheduled PUSCH resource.

Aspect 13: The method of any of Aspects 1-4 or 8-12, wherein selectivelytransmitting the beam failure recovery request for the first beam groupcomprises: transmitting, based at least in part on a determination thatthere is no physical uplink control channel (PUCCH) scheduling requestresource dedicated to beam group beam failure recovery configured in thesecond beam group, one of: a beam failure recovery scheduling requestusing a non-dedicated PUCCH scheduling request resource associated withthe second beam group, based at least in part on a determination thatthe non-dedicated PUCCH scheduling request is available, or a beamfailure recovery medium access control (MAC) control element (MAC-CE)using an existing scheduled physical uplink shared channel (PUSCH)resource associated with the second beam group, based at least in parton a determination that the existing scheduled PUSCH resource isavailable.

Aspect 14: The method of any of Aspects 1-3, wherein selectivelytransmitting the beam failure recovery request for the first beam groupcomprises: selecting not to transmit the beam failure recovery requestfor the first beam group based at least in part on a determination thatthere is no physical uplink control channel (PUCCH) scheduling requestresource dedicated to beam group beam failure recovery configured in thesecond beam group, based at least in part on a determination that thereis no other PUCCH scheduling resource associated with the second beamgroup available, and based at least in part on a determination thatthere is no existing scheduled physical uplink shared channel (PUSCH)resource associated with the second beam group available; and whereinthe method further comprises: declaring cell level beam failure for thecell based at least in part on selecting not to transmit the beamfailure recovery request for the first beam group.

Aspect 15: The method of any of Aspects 1-3, wherein selectivelytransmitting the beam failure recovery request for the first beam groupcomprises: selecting to perform a random access channel (RACH) procedureto transmit the beam failure recovery request for the first beam group,based at least in part on a determination that there are no availableuplink resources in the second beam group for transmitting the beamfailure recovery request for the first beam group.

Aspect 16: The method of Aspect 15, wherein a first RACH preamble isassociated with the first beam group and a second RACH preamble isassociated with the second beam group, and selecting to perform the RACHprocedure to transmit the beam failure recovery request for the firstbeam group comprises: initiating a contention free RACH procedure usinga RACH resource associated with the first RACH preamble.

Aspect 17: The method of Aspect 16, wherein initiating the contentionfree RACH procedure comprises: initiating the contention free RACHprocedure on a beam of the first beam group, wherein the beam of thefirst beam group is a candidate replacement beam for beam failurerecovery for the first beam group.

Aspect 18: The method of Aspect 16, wherein initiating the contentionfree RACH procedure comprises: initiating the contention free RACHprocedure on a beam of the second beam group.

Aspect 19: An apparatus for wireless communication at a device,comprising a processor; memory coupled with the processor; andinstructions stored in the memory and executable by the processor tocause the apparatus to perform the method of one or more of Aspects1-18.

Aspect 20: A device for wireless communication, comprising a memory andone or more processors coupled to the memory, the memory and the one ormore processors configured to perform the method of one or more ofAspects 1-18.

Aspect 21: An apparatus for wireless communication, comprising at leastone means for performing the method of one or more of Aspects 1-18.

Aspect 22: A non-transitory computer-readable medium storing code forwireless communication, the code comprising instructions executable by aprocessor to perform the method of one or more of Aspects 1-18.

Aspect 23: A non-transitory computer-readable medium storing a set ofinstructions for wireless communication, the set of instructionscomprising one or more instructions that, when executed by one or moreprocessors of a device, cause the device to perform the method of one ormore of Aspects 1-18.

The foregoing disclosure provides illustration and description, but isnot intended to be exhaustive or to limit the aspects to the preciseforms disclosed. Modifications and variations may be made in light ofthe above disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construedas hardware and/or a combination of hardware and software. “Software”shall be construed broadly to mean instructions, instruction sets, code,code segments, program code, programs, subprograms, software modules,applications, software applications, software packages, routines,subroutines, objects, executables, threads of execution, procedures,and/or functions, among other examples, whether referred to as software,firmware, middleware, microcode, hardware description language, orotherwise. As used herein, a processor is implemented in hardware and/ora combination of hardware and software. It will be apparent that systemsand/or methods described herein may be implemented in different forms ofhardware and/or a combination of hardware and software. The actualspecialized control hardware or software code used to implement thesesystems and/or methods is not limiting of the aspects. Thus, theoperation and behavior of the systems and/or methods were describedherein without reference to specific software code—it being understoodthat software and hardware can be designed to implement the systemsand/or methods based, at least in part, on the description herein.

As used herein, satisfying a threshold may, depending on the context,refer to a value being greater than the threshold, greater than or equalto the threshold, less than the threshold, less than or equal to thethreshold, equal to the threshold, not equal to the threshold, or thelike.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure of various aspects. In fact, many ofthese features may be combined in ways not specifically recited in theclaims and/or disclosed in the specification. Although each dependentclaim listed below may directly depend on only one claim, the disclosureof various aspects includes each dependent claim in combination withevery other claim in the claim set. As used herein, a phrase referringto “at least one of” a list of items refers to any combination of thoseitems, including single members. As an example, “at least one of: a, b,or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well asany combination with multiples of the same element (e.g., a-a, a-a-a,a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or anyother ordering of a, b, and c).

No element, act, or instruction used herein should be construed ascritical or essential unless explicitly described as such. Also, as usedherein, the articles “a” and “an” are intended to include one or moreitems and may be used interchangeably with “one or more.” Further, asused herein, the article “the” is intended to include one or more itemsreferenced in connection with the article “the” and may be usedinterchangeably with “the one or more.” Furthermore, as used herein, theterms “set” and “group” are intended to include one or more items (e.g.,related items, unrelated items, or a combination of related andunrelated items), and may be used interchangeably with “one or more.”Where only one item is intended, the phrase “only one” or similarlanguage is used. Also, as used herein, the terms “has,” “have,”“having,” or the like are intended to be open-ended terms. Further, thephrase “based on” is intended to mean “based, at least in part, on”unless explicitly stated otherwise. Also, as used herein, the term “or”is intended to be inclusive when used in a series and may be usedinterchangeably with “and/or,” unless explicitly stated otherwise (e.g.,if used in combination with “either” or “only one of”).

What is claimed is:
 1. A user equipment (UE) for wireless communication,comprising: memory; one or more processors coupled to the memory; andinstructions stored in the memory and operable, when executed by the oneor more processors, to cause the UE to: detect beam failure for a firstbeam group in a cell including the first beam group and a second beamgroup; and selectively transmit a beam failure recovery request for thefirst beam group based at least in part on a determination of uplinkresource availability in the second beam group.
 2. The UE of claim 1,wherein the first beam group is associated with a first transmit andreceive point (TRP) in the cell and the second beam group is associatedwith a second TRP in the cell.
 3. The UE of claim 1, wherein theinstructions are operable, when executed by the one or more processors,to further cause the UE to: measure a first beam failure detectionreference signal set associated with the first beam failure group and asecond beam failure detection reference signal set associated with thesecond beam failure group, wherein detecting the beam failure for thefirst beam group is based at least in part on measuring the first beamfailure detection reference signal set.
 4. The UE of claim 1, whereinthe instructions operable to cause the UE to selectively transmit thebeam failure recovery request for the first beam group are operable,when executed by the one or more processors, to cause the UE to: selectto transmit the beam failure recovery request for first the first beamgroup based at least in part on a determination that at least one of aphysical uplink control channel (PUCCH) scheduling request resource or aan existing scheduled physical uplink shared channel (PUSCH) resource isavailable in the second beam group.
 5. The UE of claim 1, wherein thebeam failure recovery request includes a beam failure recoveryscheduling request, and wherein the instructions operable to cause theUE to selectively transmit the beam failure recovery request for thefirst beam group are operable, when executed by the one or moreprocessors, to cause the UE to: transmit the beam failure recoveryscheduling request on a beam of the second beam group using a physicaluplink control channel (PUCCH) scheduling request resource dedicated tobeam failure recovery for the first beam group.
 6. The UE of claim 5,wherein the instructions are operable, when executed by the one or moreprocessors, to further cause the UE to: receive, prior to detecting thebeam failure, configuration information that maps the PUCCH schedulingrequest resource dedicated to beam failure recovery for the first beamgroup to the beam of the second beam group.
 7. The UE of claim 6,wherein the configuration information maps a PUCCH scheduling requestresource dedicated to beam failure recovery for the second beam group toa beam of the first beam group.
 8. The UE of claim 1, wherein the beamfailure recovery request includes a beam failure recovery schedulingrequest, and wherein the instructions operable to cause the UE toselectively transmit the beam failure recovery request for the firstbeam group are operable, when executed by the one or more processors, tocause the UE to: transmit the beam failure recovery scheduling requestusing an earliest available physical uplink control channel (PUCCH)scheduling request resource on a beam of the second beam group based atleast in part on a determination that one or more PUCCH schedulingrequest resources are available in the second beam group.
 9. The UE ofclaim 8, wherein the earliest available PUCCH scheduling requestresource is configured with a first spatial relationship associated withthe beam of the second beam group and a second spatial relationshipassociated with a beam of the first beam group, and wherein theinstructions operable to cause the UE to transmit the beam failurerecovery scheduling request are operable, when executed by the one ormore processors, to cause the UE to: transmit the beam failure recoveryscheduling request using the earliest available PUCCH scheduling requestresource on the beam of the second beam group without transmitting thebeam failure recovery request on the beam of the first beam group. 10.The UE of claim 8, wherein the earliest available PUCCH schedulingrequest resource is configured with a first spatial relationshipassociated with the beam of the second beam group and a second spatialrelationship associated with a beam of the first beam group, and whereinthe instructions operable to cause the UE to transmit the beam failurerecovery scheduling request are operable, when executed by the one ormore processors, to cause the UE to: transmit the beam failure recoveryscheduling request using the earliest available PUCCH scheduling requestresource on the beam of the second beam group and on the beam of thefirst beam group.
 11. The UE of claim 1, wherein the beam failurerecovery request includes a beam failure recovery medium access control(MAC) control element (MAC-CE), and wherein the instructions operable tocause the UE to selectively transmit the beam failure recovery requestfor the first beam group are operable, when executed by the one or moreprocessors, to cause the UE to: transmit the beam failure recoveryMAC-CE using an existing scheduled physical uplink shared channel(PUSCH) resource on a beam of the second beam group, withouttransmitting a beam failure recovery scheduling request, based at leastin part on a determination that the existing scheduled PUSCH resource isavailable and based at least in part on a determination that a size ofthe existing scheduled PUSCH resource is large enough to transmit thebeam failure recovery MAC-CE.
 12. The UE of claim 11, wherein theinstructions operable to cause the UE to transmit the beam failurerecovery MAC-CE using the existing scheduled PUSCH resource on the beamof the second beam group are operable, when executed by the one or moreprocessors, to cause the UE to: transmit the beam failure recoveryMAC-CE using the existing scheduled PUSCH resource on the beam of thesecond beam group further based at least in part on a component carrierassociated with the existing scheduled PUSCH resource.
 13. The UE ofclaim 1, wherein the instructions operable to cause the UE toselectively transmit the beam failure recovery request for the firstbeam group are operable, when executed by the one or more processors, tocause the UE to: transmit, based at least in part on a determinationthat there is no physical uplink control channel (PUCCH) schedulingrequest resource dedicated to beam group beam failure recoveryconfigured in the second beam group, one of: a beam failure recoveryscheduling request using a non-dedicated PUCCH scheduling requestresource associated with the second beam group, based at least in parton a determination that the non-dedicated PUCCH scheduling request isavailable, or a beam failure recovery medium access control (MAC)control element (MAC-CE) using an existing scheduled physical uplinkshared channel (PUSCH) resource associated with the second beam group,based at least in part on a determination that the existing scheduledPUSCH resource is available.
 14. The UE of claim 1, wherein theinstructions operable to cause the UE to selectively transmit the beamfailure recovery request for the first beam group are operable, whenexecuted by the one or more processors, to cause the UE to: select notto transmit the beam failure recovery request for the first beam groupbased at least in part on a determination that there is no physicaluplink control channel (PUCCH) scheduling request resource dedicated tobeam group beam failure recovery configured in the second beam group,based at least in part on a determination that there is no other PUCCHscheduling resource associated with the second beam group available, andbased at least in part on a determination that there is no existingscheduled physical uplink shared channel (PUSCH) resource associatedwith the second beam group available; and wherein the instructions areoperable, when executed by the one or more processors, to further causethe UE to: declare cell level beam failure for the cell based at leastin part on selecting not to transmit the beam failure recovery requestfor the first beam group.
 15. The UE of claim 1, wherein theinstructions operable to cause the UE to selectively transmit the beamfailure recovery request for the first beam group are operable, whenexecuted by the one or more processors, to cause the UE to: select toperform a random access channel (RACH) procedure to transmit the beamfailure recovery request for the first beam group, based at least inpart on a determination that there are no available uplink resources inthe second beam group for transmitting the beam failure recovery requestfor the first beam group.
 16. The UE of claim 15, wherein a first RACHpreamble is associated with the first beam group and a second RACHpreamble is associated with the second beam group, and wherein theinstructions operable to cause the UE to select to perform the RACHprocedure to transmit the beam failure recovery request for the firstbeam group are operable, when executed by the one or more processors, tocause the UE to: initiate a contention free RACH procedure using a RACHresource associated with the first RACH preamble.
 17. The UE of claim16, wherein the instructions operable to cause the UE to initiate thecontention free RACH procedure are operable, when executed by the one ormore processors, to cause the UE to: initiate the contention free RACHprocedure on a beam of the first beam group, wherein the beam of thefirst beam group is a candidate replacement beam for beam failurerecovery for the first beam group.
 18. The UE of claim 16, wherein theinstructions operable to cause the UE to initiate the contention freeRACH procedure are operable, when executed by the one or moreprocessors, to cause the UE to: initiate the contention free RACHprocedure on a beam of the second beam group.
 19. A method of wirelesscommunication performed by a user equipment (UE), comprising: detectingbeam failure for a first beam group in a cell including the first beamgroup and a second beam group; and selectively transmitting a beamfailure recovery request for the first beam group based at least in parton a determination of uplink resource availability in the second beamgroup.
 20. The method of claim 19, wherein the first beam group isassociated with a first transmit and receive point (TRP) in the cell andthe second beam group is associated with a second TRP in the cell. 21.The method of claim 18, wherein selectively transmitting the beamfailure recovery request for the first beam group are operablecomprises: selecting to transmit the beam failure recovery request forfirst the first beam group based at least in part on a determinationthat at least one of a physical uplink control channel (PUCCH)scheduling request resource or a an existing scheduled physical uplinkshared channel (PUSCH) resource is available in the second beam group.22. The method of claim 18, wherein the beam failure recovery requestincludes a beam failure recovery scheduling request, and selectivelytransmitting the beam failure recovery request for the first beam groupcomprises: transmitting the beam failure recovery scheduling request ona beam of the second beam group using a physical uplink control channel(PUCCH) scheduling request resource dedicated to beam failure recoveryfor the first beam group.
 23. The method of claim 18, wherein the beamfailure recovery request includes a beam failure recovery schedulingrequest, and selectively transmitting the beam failure recovery requestfor the first beam group comprises: transmitting the beam failurerecovery scheduling request using an earliest available physical uplinkcontrol channel (PUCCH) scheduling request resource on a beam of thesecond beam group based at least in part on a determination that one ormore PUCCH scheduling request resources are available in the second beamgroup.
 24. The method of claim 18, wherein the beam failure recoveryrequest includes a beam failure recovery medium access control (MAC)control element (MAC-CE), and selectively transmitting the beam failurerecovery request for the first beam group comprises: transmitting thebeam failure recovery MAC-CE using an existing scheduled physical uplinkshared channel (PUSCH) resource on a beam of the second beam group,without transmitting a beam failure recovery scheduling request, basedat least in part on a determination that the existing scheduled PUSCHresource is available and based at least in part on a determination thata size of the existing scheduled PUSCH resource is large enough totransmit the beam failure recovery MAC-CE.
 25. The method of claim 24,wherein transmitting the beam failure recovery MAC-CE using the existingscheduled PUSCH resource on the beam of the second beam group is furtherbased at least in part on a component carrier associated with theexisting scheduled PUSCH resource.
 26. The method of claim 18, whereinselectively transmitting the beam failure recovery request for the firstbeam group comprises: transmitting, based at least in part on adetermination that there is no physical uplink control channel (PUCCH)scheduling request resource dedicated to beam group beam failurerecovery configured in the second beam group, one of: a beam failurerecovery scheduling request using a non-dedicated PUCCH schedulingrequest resource associated with the second beam group, based at leastin part on a determination that the non-dedicated PUCCH schedulingrequest is available, or a beam failure recovery medium access control(MAC) control element (MAC-CE) using an existing scheduled physicaluplink shared channel (PUSCH) resource associated with the second beamgroup, based at least in part on a determination that the existingscheduled PUSCH resource is available.
 27. The method of claim 18,wherein selectively transmitting the beam failure recovery request forthe first beam group comprises: selecting not to transmit the beamfailure recovery request for the first beam group based at least in parton a determination that there is no physical uplink control channel(PUCCH) scheduling request resource dedicated to beam group beam failurerecovery configured in the second beam group, based at least in part ona determination that there is no other PUCCH scheduling resourceassociated with the second beam group available, and based at least inpart on a determination that there is no existing scheduled physicaluplink shared channel (PUSCH) resource associated with the second beamgroup available; and wherein the method further comprises: declaringcell level beam failure for the cell based at least in part on selectingnot to transmit the beam failure recovery request for the first beamgroup.
 28. The method of claim 18, wherein selectively transmitting thebeam failure recovery request for the first beam group comprises:selecting to perform a random access channel (RACH) procedure totransmit the beam failure recovery request for the first beam group,based at least in part on a determination that there are no availableuplink resources in the second beam group for transmitting the beamfailure recovery request for the first beam group.
 29. A non-transitorycomputer-readable medium storing one or more instructions for wirelesscommunication that, when executed by one or more processors of a userequipment (UE), cause the UE to: detect beam failure for a first beamgroup in a cell including the first beam group and a second beam group;and selectively transmit a beam failure recovery request for the firstbeam group based at least in part on a determination of uplink resourceavailability in the second beam group.
 30. An apparatus for wirelesscommunication, comprising: means for detecting beam failure for a firstbeam group in a cell including the first beam group and a second beamgroup; and means for selectively transmitting a beam failure recoveryrequest for the first beam group based at least in part on adetermination of uplink resource availability in the second beam group.